Thursday, April 9, 2009

How to Sleep in a Car

UPDATE (Jan. 2021): See my Car Camping Advice in a Tweet Thread.

Note: This article is about how to sleep in a car. See separate article for Where to Sleep in a Car

If you can sleep in a car, you've gained an enormously valuable life skill. Think about it: You can sleep in places where you can't otherwise afford to stay; you're protected from the elements, and the rent is free (provided the car is already paid for). Even if you don't actually sleep in a car, knowing that you can do it means that you can arrive in a new city without a hotel reservation, just a car rental reservation. If you can't find affordable lodging, you know you'll get by. [Text in red are new revisions as on 8/51/13, after I have been sleeping in cars off and on for years.]

Sleeping in a car is a form of "car camping," where you sleep in or near your vehicle (as distinct from backpacking—See Wikipedia). In terms of protection from the elements, a car is about halfway between a hotel room and camping in a tent, and if you just need some sleep it's probably easier than both. (There's no tent to set up and no check-in process to go through.) For example, if you are on a long road trip and just need a few hours of shuteye, checking into a motel may be unnecessarily complicated and rob you of still more sleep during the process of finding a room and moving in. Sleeping in the car may be just the thing!

Sleeping in a car may seem uncomfortable, but mostly it is a problem of perception and adaptation—i.e. the barriers are mainly in your head. Around the world, people sleep in all sorts of odd arrangements, and a car is among the most convenient and comfortable. Security? It's not a major issue as long as you are discreet and choose your location carefully. I will cover site selection in a separate entry, but in general, you can sleep in your car almost anyplace you would feel comfortable parking it overnight. If your car doesn't attract attention, you won't either.

But how, physically, do you sleep in a car? Basically, you just obtain a sleeping bag or other covering appropriate to the weather, find something to use as a pillow and lie down in the back seat. If you're tired, you will sleep, and once you get used to it, you can probably sleep there as comfortably as in a bed.

Sleeping in a car is an acquired skill, however, and it takes some experience to do it elegantly. Below are some considerations for the first-time car sleeper. (Again, these rules tell you how to sleep in a car. In a separate entry, I will discuss where to sleep.)

1) You MUST crack one of the windows so you can breathe. [Wrong! As long as there is just one person in the car, nothing else using oxygen and the temperature is cool, you can leave the windows completely closed all night. I wouldn't think it possible, but it works! Apparently there's enough air to keep you alive. On cold nights, keeping the windows closed definitely keeps the car warmer, but it can make it much too hot on warm nights.] It doesn't have to be much, though: For one person, a quarter-inch opening in one window is sufficient. (It doesn't seem like enough, but I have learned from experience that it is.) If you fail to open a window, you might sleep okay for a couple of hours, but you'll eventually wake up gasping for breath. (It's not like you'll die in your sleep; your body will give you plenty of warning!) A quarter-inch to an inch is a good balance between air circulation, heat retention and security (so someone can't reach in the window). In mosquito-prone areas, you might even make the opening so thin that the mosquitoes can't get in. Same thing when it's especially cold outside: Experiment with how thin you can make the opening. You need some sort of opening in the car, but it is remarkable how little it can be. (Don't worry: Your body will tell you when you need more air!)

2) In warm weather in humid areas, mosquitoes may be an issue. Even one or two in the car can ruin your sleep. You deal with this by draping some sort of light cloth over the window opening. Camping stores or Evil Mega-Mart™ may sell mosquito netting designed specifically for this purpose, but any light, thin cloth or piece of clothing will do. (You may have to open your window a little more for adequate circulation.) Mosquitoes only become active in temperatures above 50°F, and they don't usually become a significant irritant until about 60°F, so you don't have to worry about them in cold weather. Mosquitoes need stagnant water to breed in, so you won't find many of them in the desert. They are also slow fliers and are easily blown away by the wind. I find the mosquitoes are really only an issue in humid, still areas in the summer. You can't really tell whether an area is going to be mosquito-prone until you go there, but you should always be prepared. If you find yourself in a situation where you can't protect yourself with netting, mosquito repellent may get you by, but that's yucky stuff I prefer to avoid. [Hot weather and/or mosquitoes are the one situation where car camping just doesn't work, especially in the Southeastern USA. Cold is no problem because you can always add bedding, but heat and humidity can force you into a motel.]

3) You can sleep in a car even when it is very cold outside, provided you have enough bedding. I have done it in temperatures as low as 0°F/-18°C. (by sleeping in three sleeping bags: one inside the other and a third one on top of me). The car protects you from rain and wind, which are very significant elements in keeping warm. The enclosed space is also warmed by your body heat, so the temperature inside is significantly warmer that the air outside. (That's one reason to keep the window opening small.) One consideration when sleeping in sub-freezing temperatures: In the morning you may have to scrape frost off the INSIDE of the windshield. One nice thing about sleeping in a car is that you can reach over, turn on the car's engine and warm the place up before you get out of bed!

4) Whenever possible, you should consult on-line sources to find out what the weather is expected to do overnight. The key statistic is the overnight low temperature. With experience, you'll learn what kind of bedding you need for various temperatures.

5) The best kind of bedding is a sleeping bag, since you can zip it up around you and eliminate drafts. Basic models at Walmart start at $15 (but I usually get the $20 model). You'll probably get more insulation value by buying two cheap sleeping bags, one inside the other, than one expensive one. The temperature ratings labeled on the sleeping bag are pretty much a fantasy; you'll have to experiment to see what works at various temperatures. In the 80s and above (°F), you may need no sleeping bag at all, maybe just a thin blanket. Between 50s and the 70s, a standard sleeping bag might do. Much below that, you'll probably need multiple sleeping bags. In my experience, there is no degree of cold that can't be addressed passively by adding more layers, but I've never tried to camp in Alaska. [Now I have slept in Alaska in the winter at -10°F, and it worked. See my winter pix from the Alaska Highway. I had two Walmart sleeping bags, one inside the other, covered with a third draped over me. I also wore two layers of thermal underwear and all my clothing. Slept like a baby. Conclusion: Cold is never a problem with enough bedding.]

6) A simple and extremely useful device is a single standard safety pin. A sleeping bag zips up around you, but it can easily become unzipped at night. The safety pin can be used to fix the zipper at the top.

7) Vans, mini-vans and large SUVs may give you more opportunity to stretch out, but they are colder than regular cars because your body has more space to heat. When renting a car, I usually go for a full-size or mid-size sedan as a good balance between space, warmth and cost.

8) In rainy or snowy weather, water is going to come in the window opening. You can prevent this by draping a sheet of plastic over the opening. (In rainy and mosquitoey conditions, you might need both the plastic and the thin cloth.) Alternatively, you might be able to make the gap in the window so small that the rain can't get in. [Not necessary, just close all the windows! The only problem is when the weather is both rainy and hot. Then you're screwed.]

9) Snow is usually no problem! A layer of snow can actually warm the car by providing more insulation. Snow usually happens when the outside temperature is hovering around freezing, so snowy nights are usually warmer than clear nights at the same time of year.

10) If you are forced to sleep in a car in cold weather without sufficient bedding, you can consider leaving the car running and the heater on. I am concerned with unnecessary wear on the engine, so I would be more likely to do it with a rental car than my own. I am not too concerned, however, about carbon monoxide poisoning. Modern cars are well-sealed, and if the heater is blowing air into the car and one window is cracked open, I feel safe. As an added protection, I might gauge the wind direction and park the car pointing into the wind. (People do occasionally die from carbon monoxide poisoning in running cars parked in enclosed spaces like garagesbut it is usually intentional. You have to work at it.) Don't use anything like a gas heater in the car. That's just asking for trouble. It is safer (and probably more effective) to simply keep the windows rolled up. A lack of oxygen and excess of carbon dioxide will wake you up, whereas carbon monoxide kills you quietly.)

11) Very hot weather is the only time car sleeping might not work. You may have to fully open all of the cars windows to be cool enough, which makes you vulnerable to mosquito attack in humid areas. This is when you may be forced to move to a tent or even a motel room. In the desert where there aren't any mosquitoes, you don't even need a tent: You just sleep on an air mattress in the open. (Even when the daytime temp approaches 120°F, desert nights are always pleasant. Heat retention, however, can make the car unusable.)

NOTE: We in the industrial world are so accustomed to air conditioning that we may think we need it to sleep. In fact, nighttime temperatures are usually much cooler than daytime ones, and we need air conditioning only to remove the heat that builds up in buildings during the day. If you are directly exposed to the outside air, you rarely need the A/C. [Summer in the Southeastern USA and similar parts of the world can be a total bitch where your only option is an air-conditioned motel room. I'm tough, but not that tough.]

12) Unless you are very short, you won't be able to stretch out full-length in the back seat. You'll have to bend your knees. Sleeping like this is an acquired skill, and it may take several nights to get used to. I can sleep comfortably in the back seat of ANY car, even tiny ones in Europe. In small cars, you are almost sleeping in the fetal position. You don't have to lie flat to sleep; the important thing is that your whole body is at about the same level.

13) Several times during the night, you'll have to turn over. Your body wants to do this to prevent bed sores on one side, and if you can't turn, you'll wake up. During the day, you can practice how you are going to turn in this tight space. As long as you have two different positions to sleep in (Side A and Side B), you'll do okay. Handles above the doorframe are a nice little comfort feature because you can reach up to them at night to help reposition yourself.

14) While the back seat is usually best, you can sometimes sleep in the front seat. It depends on whether there is a console between the seats and what materials you have to mitigate it. Sometimes, in a car with bucket seats, you can build up both seats with suitcases or some form of padding so you can sleep comfortably across the console.

15) If you have no choice, you can try sleeping in the sitting position (say, if you are in a car full of people or cargo). This is never very comfortable, but it's no worse than sleeping in an airplane. You usually have more reclining space available to you than an airline flier does, so it's more like a First Class seat than Coach. Sleeping for a few hours upright might get you by, but you can never get truly healthy and restful sleep unless your whole body is at the same horizontal level. [I am finding it a lot easier to sleep in the sitting position with the practice of many overseas flights. Today, I can sleep in the driver's seat just fine.]

16) Obviously, you ought to pee before you attempt to sleep. Otherwise, you'll be waking up at night with the urge and possibly nowhere to relieve it. If you need to pee throughout the night, it is usually the result of a caffeine addiction. (See Things You Don't Need: Caffeine.) If you drink less, you'll pee less. If young children can last the night, you should be able to also. [At least you can stop drinking caffeine a few hours before you go to bed.] Before you go to sleep, you want to plan where you are going to relieve yourself in the morning. If you awake before dawn, there may be more options available to you than waking during the day. A pee bottle (or proverbial "pot to pee in") could be helpful, so be sure you have something to use for this. As for—ahem!—solid waste, you should know when in the day it usually happens and plan for it. (An actual restroom is best. Walmart, gas stations or fast food joints are good.) Again, excessive production of solid waste is usually a result of excessive intake.

17) Brush your teeth before you go to bed! Free sleeping is no excuse to ignore dental hygiene. Contrary to popular belief, you don't need water to brush your teeth, just a toothbrush and toothpaste. (I use a battery operated SonicCare™ from Walmart.)

18) You should probably sleep in your regular street clothes (or loose-fitting clothing that looks like street clothes). For one thing, this adds an extra layer of warmth, but you also want to be fully clothed in case you are woken at night by a police officer or security guard. (I'll discuss these potential interruptions in the entry on siting. It's usually benign. The worst they can do is ask you to move elsewhere.) Where possible, your clothing should be loose-fitting and comfortable. Ladies will probably want to de-bra, and gentlemen will want to loosen up "down below" (due to nighttime expansion). To the Free Sleeper, special night clothes or pajamas are an unnecessary vanity.

19) Some kind of sleeping hat is important to curb heat loss through your head. Your body places a high priority on keeping your head warm, so even if you are inside a warm sleeping bag, you could still be cold if your head is fully exposed. A knit winter cap does the trick, but if you don't have one, you can use a spare t-shirt: Just turn it upside down, stick your head halfway through the neck opening, and—Voila!—you have a sleeping cap. It makes you look a bit like an Arabian sheik, but it may be warmer and more likely to stay on your head than a knit cap.

20) Whenever I am sleeping in a position that I regard as unusual or uncomfortable to me, I usually take an aspirin tablet or two before going to sleep. This is specifically for my back (see my blog entry on it), but it also might address other muscular aches and pains before they happen.

21) If you need to get moving at a certain time, be sure you have some kind of alarm clock to wake you. A cellphone alarm will do, but it is very important to know your alarm clock. (Many times, I thought I set my alarm only to discover too late that I had done something wrong.) Greater than the risk of sleeping too little is the chance of oversleeping. Some parking locations that are very secure and discreet at night can be too exposed during the day, so you should consider whether you want to wake up and move on before dawn.

22) Unless you are in a very remote location with little chance of human interaction, when you wake up you probably want to get in the driver's seat and drive away as soon as possible. This gives you the warmth of the car's heater, but it may also address a security issue: When you are awake, sitting up and moving, it is easier for others to detect you. As with urban camping, I don't like to mix venues: The place where I camp is used only for sleeping, not for anything else, like eating or working on the computer. As soon as the sleeping function is complete, I move elsewhere.

Have I forgotten anything? We have yet to get into the social aspects of car sleeping—namely where to do it without attracting attention, but the above should cover the physical issues.

See separate article: WHERE to Sleep in a Car 

9 May 2020 — Video from 2015 added.


  1. Very interesting. I sometimes sleep in my car; I will probably do it tomorrow night as I'm moving to a new area. My car is very small, the back seats are full of stuff, so I have to sleep in the front. It is a bit uncomfortable, but I'm getting better are it. Your tips are useful.

  2. I'd never had no choice but to sleep in my car before the last week or so. Thanks for the blog, made me feel a bit better. ^_^

  3. In total I have spent at least half a year of my life sleeping in cars. One useful tip which has been omitted in the article - don't bother about sleeping on the seats (front or back) - it sucks. The best sleep you can get is by folding the back seat and moving the front seats all the way to the front. Sounds crazy? I did it hundreds of times in a Nissan Micra (it's too small to be marketable in the USA - try to google it, it's unimaginably small as for the US market). I'm over 6'' and there were usually 2 of us inside. What you get by folding the seats is a nearly flat space, about 5 feet long! For me, it's way better than a hotel. That's how I have explored some 15 countries (in Europe and America). Oh, and remember - keep your head in the trunk! Enjoy

  4. I tried something like that in my early car-sleeping days. Now, I find that sleeping in the back seat of a car works best. Even in tiny European cars, I can curl up in a fetal position and sleep in almost any space. The convenience of the back seat is that it is well padded (so you don't have to bring any additional padding), and it's easier to keep warm in that tiny space. If no back seat (or two people), you can sometimes build up the front seats to sleep over the console.

  5. Careful with the carbon monoxide from car engines. It's heavier than air, so it sinks. Cracking a window at the top won't vent it (this is why camper vehicles always have an air vent somewhere low, like in the bottom of a door). If you use the engine to heat up the car, switch it off before you sleep.

    About the windows, people have died in cars without the windows open - even without the engine running - because a lack of oxygen won't necessarily wake you since it makes you drowsy! Buy a lottery ticket because if you have woken up and felt the air was stuffy, you've been very very lucky. :)

  6. It's difficult to compare with the Fahrenheit, measurement you guys use. But my house is 16c at the moment - plenty warm.

    A cheap $10 sleeping bag will make you comfie down to about 10c.

    If you want to be comfy in lower temperatures you need to start looking at 'Season' rated bags. 4 Season is the minimum - You will be good down to 5c. 5 Season a bit more.

    Unfortunately, though you will be warm, when you emerge it will still be fecking cold.

  7. Clear out the trunk, or just make a space for your feet in it, open the hatchway to the trunk and lay it forward, and sleep with your feet all the way in the trunk and head up by the front of the rear seat. In a lot of cars this will work.

    For impromp

    For extended periods, consider removing the passenger front seat and storing it somewhere (usually just held in with 4 bolts (even in the woods by where you are parking) ) and building up that area to make a mini couch that includes the back seat. You can even customize a folding cot that fits over the back seat and has extra long legs down in the front seat area of the passenger side.

    If you're really serious about quality and longevity of your stuff, skip the cheap bags or even the expensive bags and buy a Wiggy's sleeping bag. Any other is to some extent a waste of money in my opinion. An opinion I share with the maker.

  8. This is awesome work Glenn. Youve done a wonderful job sharing this with the masses. Keep up the good work. Many thanks

  9. i love sleeping in my car! In fact I like it much better than a huge ugly bloated house. i sleep in the front seats most of the time, but park on a hill. i sometimes bunch a blanket in the middle of the seat making it more flat. and if you want you could put your bag or some things where your feet go.

    What has EXTREMELY HELPED ME IS TINTING YOUR WINDOWS!!!! make sure the back ones are darker than the front ones and no terrorists (they call themselves police nowadays) will bother you.

    Make sure your car looks average, clean, inside and out. No stickers.

    Other suggestions would be a popup sunscreen for the front and try to park under trees or near shade so that you can sleep longer..

    Walmarts parking lots are great places, so are apartment parking lots, hotels, rest stops, quiet streets on blocked neighborhoods near cities. Be respectful.

    Go to bed by 12 if you can help it.

    Get a power adapter $30. hook it up to your cig lighter or battery and now you have a charger for your electronics/ batteries!

    Invest in a HEADLAMP, or tiny light.

    Ipod touch's are incredibly useful. buy an older model off ebay for fairly cheap (nothing older than third gen), even cheaper if the glass is cracked. Get near wifi/ internet and Set up google voice and talkatone and you have a free unlimited phone and sms text machine with your own personal lifetime number, as well as maps, note taking, put all your books on there (ebook reader), music, note taking, pictures, video (if it's a 4th gen), you can surf the internet... you can even make music on it. (or any ipad or tiny computer will do)

    dress simple. (black or dark colors cause it doesn't get dirty)

    buy some lavender/ tea tree oil for staying fresh.

    have water with you, refill it.

    keep most of your things in the trunk/ out of sight.

    be happy. your now way better off than most people! (other than you have to pay for gas and insurance and all the bs dmv stuff.) No more 500 year mortgage bs.

    Make it look good! Houses are for homeless people.
    Earth is my home and I don't feel we should have to pay to live on the planet we were born on.

    Your car a beautiful solarium/ minimalist mobile home!! even when im staying at other peoples houses, i prefer to sleep in my car. Less mess. Imagine a world where we all did this? how awesome would that be!!!

    Housing and food is a right not a privilege. But because I'm outnumbered presently, i practice active non participation and common sense. Most things nowadays (death culture) dont make any sense, cause everyones too busy trying to survive and not living.

    YAY :)

  10. Love your posts and philosophy, but your lack of caution with carbon monoxide scares me. It only takes one car with a leak to allow this odorless invisible gas to leave you dead or maybe worse physically and mentally crippled for life.

    A portable detector is cheap insurance if you sleep in running vehicles.

    ~ Alan

  11. thank you. I need these tips for a few nights on a bumpy relationship at home. Bless you all.

  12. Thank you for making my first homeless night bearable. Found a good spot near the ocean and woke up to hear the waves crashing. Totally forgot I was in my car when I woke up.

    I do have a ventilation comment tho: Don't forget to leave the A/C-heater vent OPEN. I also thought that the sunroof is best to crack open if you've got one. Less conspicuous. Plus, it has built in drains for all but the worst precipitation.

    Finally, spend a couple of bucks to wash your car. $5 gas station wash will do. Just get the dirt off. If you are accosted by the fuzz they will be less likely to classify you as a "Bum".

  13. I'm asking myself about traveling in Uk ( first in London ) using a car to sleep ( less expensive )

    I like what you tell about your experience. It makes my hope more real.

    Can u tell me if it's possible to find a place to stay with your car for a night ( parking, etc... ) and how much it is ?

    THX !

    1. For anyone in the future that might consider this:

      Car parks anywhere near London are rarely free and they seem to be more vigilant about abandoned cars. It might be possible to park along some suburban streets in the greater metro area, but I'd be worried about choosing the wrong location.

      Due to expensive rental cars and petrol/diesel prices, I'd strongly recommend using their extensive railway system with a BritRail Pass, stay in hostels in cities, and B&Bs in smaller towns. Much safer, faster travel in the city of London, easier, and it allows you to see more of the scenery. Their cities and towns are very compact and can be quite difficult and/or expensive (tolls) to navigate in a car. If you do decide to drive and can't find a suitable spot to sleep in the car, I've noticed that M road "exit" hotels (that's what I call them - they're like private rest areas around a petrol station with an attached hotel) in remote areas tend to be very inexpensive, roughly on a par with or less than similar Motel 6 locations in the US (also, curiously-enough, if I had to sleep in a car somewhere in the UK, a car park at one of these is about the safest place I could think of).

      I recommend only renting a car when you really need it since the BritRail Pass (must be purchased in advance) is incredibly reasonable for the amount you can use it.

  14. Great tips. I use a CPAP (night-time breathing mask that pumps normal air into my nose). Found out it uses very little power, got a perfectly matched voltage car-lighter adapter at Radio Shack. When I car-sleep in cold weather, it acts as a scuba, so I can totally cover my head with a fleece blanket or third sleeping bag.

  15. I just spent my first full night boondocking in my Toyota Yaris - from 9 p.m. to 7:30 a.m. in a travel center in West Virginia. Very successful but I'll add things I learned from here to what I learned from there. You can get visor vents for windows if you have the bucks - I'm gonna save up. Going to make some window curtains out of Reflectix that require nothing other than measuring and cutting, which I got from here (age 64 hoping to go on the road in something bigger than my Yaris soon since I can't afford my house anymore).

  16. Slept in boot/trunk with legs sticking out thru opening of backseat in handful of countries.

    Planning to acquire an estate/station wagon at home to sleep on airbed in the bed.

  17. If the trunk is wide enough to stretch out that is where I sleep. A slab of foam a sleeping bag and a pillow, hey who needs a motel? Ways to disarm or remove the latch are endless and a common sense issue. A few feet of masonry twine and I can adjust the opening as I want it. I know somewhere someone is saying (whiny voice)but I'm claustophobic, I could be trapped bla bla bla Duh, you should probably stay home anyway.

  18. I am houseless and sleep in the car. I have a 4-door sedan and have removed the passenger seat. They are just held in place with 4 bolts. This allows me to sleep laying flat with my feet up on the back seat. It is actually comfortable! I use folded towels to build up the space between molding on the floor. I had been sleeping in the drivers seat and my feet and ankles swelled up. Its summer here, so its hot even at night. A fan that plugs into the cigarette lighter keeps me from waking up due to being too hot. I can run it all night and it doesn't drain the battery.

    1. Interesting, I was going to ask if anyone ever takes the passenger seat out! I might do that.

  19. This is all ok for guys, but a single woman sleeping in her car anywhere at night could pose a potential threat to her. I am moving from New York to Texas on a micro budget. I am stressing about where to stay cheap on my way there. I have thought about sleeping in my car in places like Walmart parking lots, rest stops, etc., but the thought of being scoped out by men with rape on their minds, seeing a female alone in a car at night is just too frightening for me. Can anyone tell me where I can stay for three nights cheap from New York to Big Spring, Texas? I don't want to learn to sleep in my car, I would rather pay a little money and be safe in a room somewhere, but I don't have a lot of money to spend. Moving on a budget of $1000.00 or less. Thanks.

  20.'s cold and sleeping in my car to save money. What about places to shower....yes. brush your teeth. Thanks I am worried about carbon monoxide poisoning

  21. I am a single woman, and I have slept in my car. Not intentionally, but Ive done it 4-5 times at least. I had long drives, where I needed only to sleep 4 or 5 hours, and it made no sense to pay $100+ for a few hours sleep. Especially when you have a lot on hour mind, and after the hassle of checking in and getting situated, you find that you dint even sleep that much. I sleep in the parking lots of the places I would stay if I had cash to burn, i.e. Holiday inn express, etc. Its funny to read this article, because for me, I first started doing this when I had to travel from denver to detroit for my grandfathers funeral. I had very little money, and needed to get there asap. Next thing you know I did it again on the reverse trip. Lol. Then again for a different trip. Then again. Now I want to visit Charleston, apparently an expensive town. The difference is, before Id only sleep 3-5 hrs in the car, then continue to my destination. This would be WAY more time sleeping and/or resting in my vehicle. I dont know....