Is it Warmer to Sleep in a Tent or a Car? My Tips

Both in Europe and the USA, there were some nights in which I had both a rented car and a tent. In this situation, you are facing a serious dilemma – is it warmer to sleep in a tent or a car? Over the years, I was able to learn about the advantages and downsides for each one, although I felt it wasn’t enough and the question remained unanswered. That got me researching the topic a little deeper, mainly to form a more established opinion on the matter.

It is warmer to sleep in a tent rather a car when you are well-equipped – that’s because tents feature a smaller volume (that could warm up faster) and double-layer insulation. Besides, tents are made of polyester fabrics which doesn’t get cold as much as aluminum, mainly due to their lower thermal conductivity.

Still, consider that cars would do better under severe conditions, mainly because they are entirely sealed and far from the ground. Besides, you may use their heater, although you should take the right way to do it – I will elaborate on this later on in the article.

Also, cars have a better start point than tents since they are usually already warm due to the engine heat – that would make you more comfortable until you fall asleep.

Tent Advantages

  • Enjoy a Campfire
  • Smaller Volumes Heat Faster
  • Double Layer Insulation
  • Less Thermal Conductivity
  • No Battery Issues
  • More Sleeping Adjusted

Car Advantages

  • You May Use The Heater
  • Has a Better Start Point
  • Dry Inside
  • Far From The Ground

Enjoy a Campfire

The first advantage I find worth mentioning regarding sleeping in tents is that you can use a campfire to get your warm – in opposed to sleeping in a car. 

If you ask me a campfire is the best way to keep yourself warm during nighttime, especially when you are using one which burns for hours.

If you are less familiar with the techniques, I highly suggest that you read my article on building a campfire which would last all night – I’ve spent a whole day to gather you the most useful methods – followed by pictures and videos.

Smaller Volumes Heat Faster

When camping without any heaters or fire, the primary source for warmth is your body. When you are lying in your sleeping bag, for example, you warm up because the down (or synthetic) materials trap your body heat and prevent it from escaping.

If you rely on your body temperature to keep you warm, there is no doubt you would do better with tents. Even if you use blankets (or perhaps even a sleeping bag) in your car, a heat portion would still escape. 

However, a tent would still get warmer and create a more comfortable environment outside your thermal barrier.

Double Layer Insulation

Another advantage is that tents usually feature a double wall layer. I will elaborate on that technology later on in this article, although I will say now that this structure creates an air barrier between the layers.

If you ever flew in an airplane, you’ve probably noticed that the windows there feature the same characteristics. When you touch the windows from the inside, the temperature you feel is no way near the one which is outside.

The air trapped in between acts as an insulator and does its job best when the gap is narrow enough. In opposed to tents or airplanes, cars feature a single glass layer which gets cold quickly and drops to a temperature which is relatively close to the outside.

Less Thermal Conductivity

Have you ever been asking yourself: “Why does a pot get much colder in a refrigerator comparing to an empty glass?” Maybe I’m the only nerd here, although the factor does play a role when you have to decide whether or not to sleep in your car.

The term I am referring to is Thermal Conductivity which is a familiar topic in the field of thermodynamics. In simple words, the higher the number, the more easily it conducts heat. 

The role could be played both ways – the object would get colder as much as easy that it would get hotter. A significant portion of car doors is aluminum, which features a thermal conductivity of 225.94.

Polyester fabrics, which is what tents are made of, feature a much smaller value – approximately 0.05. From these number, we learn that when placed in the same environment, car doors get much colder than tent walls.

No Battery Issues

As I’ve already mentioned, one common way to keep yourself warm during nighttime is building a long-lasting campfire. The equivalent for this, in the field of cars, is keeping the heater on all night long.

When your engine is turned off, heaters consume energy from the battery in your vehicle. The primary purpose of this battery is to start up your car when the engine is off. 

That doesn’t require much energy, although if the battery is dead – you are stuck. Let’s say you own a 120-watt heater; if you divide that number by twelve, you get the number of Amps it draws from your battery (120/12=10 Amps).

Then, multiply it by the hours you anticipate the heater would run (if a whole night is 8 hours, then it would consume 10*8=80 Watts from your battery).

If the battery features a lower number than that – it would probably get worn-out in the morning, and the engine won’t start going.

More Sleeping Adjusted

Let’s admit it – cars are for driving and tents are for sleeping. That is a broad and rough generalization, although tents are usually roomier. 

There is lots of variability in this since it depends on the size of your car and the number of people you are camping with.

If you are camping with an SUV or a Jeep – you would probably do fine if you are camping by yourself or only with a single friend or spouse. Still, if you are camping with your entire family – I think getting a family tent is a better choice. 

When there are too many people in a car, you usually have to open your windows a little wider. That, in turn, would bring cold in and in worse cases even raindrops or snow.

You May Use The Heater

I’ve said before that using your car heater the whole night may consume the battery and would make it impossible to start your vehicle in the morning. However, that statement is less relevant if you use the heater for short periods. 

The scenario which pops to my mind is that you can turn the heater on once you’ve woken up due to cold and sunrise is about to take place. There is no doubt that a heater would get you warmer much quicker than a campfire and is a better choice if you use it wisely.

Concerning that, you must make sure that you don’t park in a closed area with no ventilation – that would increase risks of carbon monoxide poisoning which comes from the car exhaust.

Has a Better Start Point

Are you familiar with the inconvenient feeling when you enter a cold sleeping bag? That is the problem when the source of heat is your body – it takes time until it gets warm and in the meanwhile, you are freezing.

What I like about sleeping in a car is that when you turn off the engine, it’s core temperature stays high for an extended period. 

This way you may feel comfortable just as you go to sleep, although you should consider that it doesn’t last forever and the car would get colder in the following hours.

For that reason, I suggest that you sleep with enough layers even when you feel it is too hot at the moment – you won’t notice the drop in temperatures until you wake up the next time.

Dry Inside

The big issue with tents is that many times condensation occurs. I’ve been talking about it widely in my article in which I was researching the reasons why your sleeping bag might get damp

If you haven’t read it already – please do, I’ve described all the different scenarios I could find and offered each on an elaborated solution (literally spent more than ten hours on the topic).

Well, cars are entirely waterproof – there is no chance water would get in from the bottom or sides as might happen in tents. 

Still, if you go with the sleeping in your car option, I suggest that you leave your windows a bit open – that would improve ventilation and prevent condensation that comes from your breath and sweats.

Far From The Ground

The most significant way in which you are going lose heat when camping is being closed to cold ground. That is why I highly recommend that you use a sleeping pad, which makes it more comfortable to your back and acts as a thermal barrier.

You may find more information regarding foam and air sleeping pads in my article – I’ve collected the pros and cons for each one and offered final thoughts on choosing the right one. 

Well, cars don’t have that problem – they are relatively far from the ground due to their high tiers.

Can I Use Both?

Yes, and frankly – if you have a large tent which may cover your car – that would be my way to go. Your tent may be the perfect insulator and act as a blanket to your vehicle. 

Although, you shouldn’t start your car to use the heaters while it is covered with canvas – that would increase the likelihood of CO intoxication. 

You can use the tent poles to hang it in a way it would block snow from accumulating, although if you own a small car, there is a good chance a tarp would get the same job done.

What is The Best Way to Keep Yourself Warm in a Car?

If you’ve chosen to sleep in a car, you should take the necessary means to keep yourself warm as much as you can. Start with the outside and cover your vehicle with a tarp or a large tent if possible, as just mentioned. 

If you don’t have any of those and it’s getting snowy – take a thin layer of snow and cover your car front and top with it. That might sound paradoxical; however, snow acts as a pretty good insulator from cold air and winds.

Regarding clothing, I suggest that you sleep with your sleeping bag and a liner if possible. For more information regarding the necessity of sleeping bag liners, read my article which describes all the different activities in which they may serve a decent purpose. 

Sleep with clothes on and make sure that they are entirely dry – it is far better than sleeping naked which I’ve explained deeply in a different article

Sleeping with clothes improve thermal insulation, although you shouldn’t exaggerate with these – having too many layers may cause sweats and a damp sleeping bag.

What Should I do if I Get Stuck in My Car?

I hope that you will never get to this, although if you hesitate between sleeping in your car or tent, there is a good chance you are facing some harsh weather conditions.

Whether your battery dies out or you are buried in snow, there is a chance you will get stuck in your car when things get rough.

My first advice to you would be staying inside. If you are parking in a place which is frequently visited, there is a better chance in being found rather than reaching for help (not to mention that your car is your only permanent shelter when the weather is not on your favor). 

If you have a mobile phone with you, take a chance and call a friend for rescue – there is a chance you will get reception once in a while.

On that matter, I suggest that you buy upfront a rescue transducer that would get help in the touch of a button. If you are using gas for heat – make sure frequently that your exhaust doesn’t get covered with snow, to prevent CO accumulation.

What Should The Sleeping Bag Feature?

First, your sleeping bag should be down-filled. There is no doubt that down keeps you warm better than synthetic, although could be a little more expensive. 

Second, I suggest that you invest in a Gore-Tex sleeping bag cover – it does increase the price, but it ensures the best water resistance.

I also recommend that you use your sleeping bag loops to keep your mattress and liner fixed at placed – read about all the different requirements those loops feature in this article I’ve written.

When Would a Tent be Better?

Well, the answer for that mainly depends on the quality of your gear. If you have a proper down-filled sleeping bag with sufficient thermal insulation – you could even endure temperatures under 0 degrees. 

Also, you should use synthetic or wool base layers which are entirely dry and haven’t got any damp during your walk.

If you have all these, in addition to gloves and a proper sleeping pad – I think you can feel confident in sleeping in extreme weather conditions without using a car. 

A car would be a better choice if you gear isn’t warming enough and when some severe winds are taking place. If you haven’t taken the time to build a durable shelter – take extra precautions and stay in your car for the rest of the night.

Why do Tents Have Two Layers?

At the beginning of this article I’ve mentioned that modern tents feature two-layer walls for a reason; now it is time to get a little deeper into it.

In general, high-quality tents were designed so that they will be able to repel water while maintaining ventilation. Their inner layer is usually pored and features tiny holes to keep air circulation – that decreases condensation which comes from sweats and breathes. 

On the other hand, moisture from the outside gets blocked by the outer layer of the tent, which is usually coated with polyurethane – a water-resistant material.

Conclusions

There is no one verdict regarding which way is better since it depends on a wide range of variables. The essential ingredient in the equation is the gear you have and its capability of enduring extreme conditions.

As I’ve said, with the right equipment, there is no doubt a tent would be the better way to go, since it insulates better and gets warm much quicker.

If you find it hard to decide – use may use both, by covering your car with your tent, which acts as a huge blanket. Although, when going with that approach, you should leave a gap from the car exhaust, so it doesn’t accumulate toxic fumes.

The proper sleeping bag should be down-filled and feature a Gore-Tex water resistance technology – even though it’s expensive, there is no doubt it worths the price.

I hope my article has pointed you in the right direction and helped you to establish a solid decision. There is a lot to take into considerations, and for that, I’ve dedicated this writing.

If you have any hanging question or enlightening points of view – let me know all about them by leaving a comment below!

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