One of the major concerns about sleeping in a car overnight besides safety issues is keeping warm, most especially during cold seasons like winter.
To stay warm in a car overnight, you will need to wear warm clothing such as jumpers, gloves, and socks, warm bedding like wool blankets to lie on, and additional heat sources like a portable heater, candles, and disposable heating packets for your hands and feet.
Nonetheless, these are just the basic items you will need. To know more about how you can keep warm overnight, read further down below for a more detailed explanation.
Pro-tip: If you want an overnight car heater to keep things even warmer, I recommend checking out the best overnight car heaters on Amazon.com.

Wear layers of warm clothing to maintain body heat.
Before thinking about adding any more heat, focus on your own body heat. Dress in warm and dry shirts, pants, sweaters, jumpers, socks, mavins, gloves, and any other additional clothing. Layering up on your clothes prevents your body heat from escaping, therefore, keeping you warm overnight.
Use space, mylar, or thermal blankets to keep warm.
Also referred to as emergency or shock blankets, these are lightweight blankets made of impermeable plastic sheets that trap body heat that would otherwise be lost through radiation.
However, they aren’t insulative to mean they can’t block or reflect back heat. Furthermore, they don’t generate heat as other types of blankets would. Nonetheless, they are very effective in protecting against hypothermia and shock.
If you choose to use a mylar blanket, be sure to use additional cold-weather bedding as those discussed in the next point.
Invest in warm bedding like wool blankets.
The car is not a conducive place to sleep, but it can be if you invest in cold weather bedding such as cotton or wool blankets/ duvets, velvety flannels that offer not only insulation but also comfort and coziness, fleeces, and a coverlet.
You can opt to use one or all these bedding options to keep you warm and subtle throughout the night.
Buy a portable heater for additional warmth.
If your car heating system/ HVAC system isn’t working properly or at all, this is a great alternative. Portable automotive heaters come in all shapes, sizes, and designs to meet your needs. Furthermore, there are different types of car heaters, such as electric, fuel-powered, and catalytic heaters.
Since you will be in a small enclosed space, a car, the best option is a catalytic heater. Here’s why:
- They don’t produce carbon monoxide. Most heaters create heat energy by mode of combustion. However, catalytic heaters only speed up the heating process and don’t allow for molecular changes in the gas that would otherwise result in the emission of co2.
- They are highly efficient. These heaters use either propane or butane fuel that’s fuel-efficient compared to liquid fuel.
- They are generally safer. Unlike regular heaters, you can use this type for longer periods without the need for ventilation.
Insulate the car with reflective foam.
To maintain any heat you generate inside the car, you need to insulate the car from within with a reflective foam that will bounce back the heat energy. Purchase a large roll of reflective foam of your choice and fit it onto your windows and the windshield. Ensure you cover the windows from inside and not from the exterior as you would when the sun is blocking your car. This way, the heat remains within the interior of the car.
Alternatively, you can insulate the car with a space blanket. Cover your windows and the windshield with the space blanket, then also use it to cover yourself.
Run the car’s engine to utilize the HVAC System.
This is the most sought after solution to staying warm in a car overnight because it’s fast and readily accessible. You simply use the car’s heating system and generate fast heat. However, it carries a huge risk.
Running the car’s engine will utilize the vehicle’s fuel fast – say in five hours, your full tank will be exhausted. Moreover, it’s not advisable to sleep with the car engine running because it poses dangers. These include:
- Carbon monoxide poisoning. Annually, at least 430 Americans die from accidental CO poisoning. Furthermore, approximately 50,000 people visit the emergency department annually for the same reason. This is because since carbon monoxide is odorless and colorless, you won’t know the extent of your exposure until it’s too late.
- Suffocation due to the air exhaust system. The HVAC system utilizes the same oxygen you need to breathe. Hence, with the engine running, you’re depriving yourself of the much-needed air.
If you want to use your car heating system, ensure its working properly, only run the car engine in short intervals, or invest in a carbon monoxide detector that will monitor the gas levels and alert you in case of excess co2 levels.
Rehydrate with hot drinks carried in a heated mug.
Another simple way to keep warm overnight is to carry along with you a cup of warm drinks. Place it in a heated mug or flask and occasionally drink to keep your body hydrated and warm. The heated mug is electrically plugged into the car’s socket, keeping the drink at a temperature of approximately 140°F (60°C).
You can also carry packed food to refuel your body. Use electric food warmers to heat up your food before you eat.
Purchase warming packs, plug-in seat warmers, etc.
Warming accessories are also essential in keeping you warm. Here are a few accessories you should opt to purchase:
- Plug-in seat warmers. These are electrically connected seat covers that offer warmth and additional comfort – more especially for leather seats that don’t retain heat.
- Heated car steering wheel. If you are driving rather than sleeping throughout the night, this can come in handy to prevent your hands and fingers from freezing.

- Disposable heating packets. These warming packets are very common for use on your hands and feet. You simply hold onto the packets for some time and they conduct heat, keeping you warm all night.
- Warm floor mats. You can replace the mats in your car with something warmer that will not only soothe your feet but also keep them warm and prevent them from getting frostbites.
- Candles. They don’t emit as much heat as a 12v car heater would, but using two or more candles can accumulate enough heat to keep you going.
Use an electric blanket.
An electric blanket is a type of blanket that’s integrated with electrical heating wires. They work similarly to heating pads, where an insulated wire is fitted into the fabric that heats up once connected to power. Most will have a temperature control unit where you regulate the heat emission by managing the amount of current entering the heating elements.
The blanket can be used as an underblanket, a throw blanket, a duvet, or a coverlet. The best way to use an electric blanket is to heat up where you will be sleeping and switch it off or remove from the power source before you sleep. This way, you’re not sleeping on heating wires.
Note: The electric blanket will drain your car’s battery; therefore, only use it for a short while.
Final Thoughts
Well, there you have it, with the nine effective tips above you can easily stay warm in a car overnight. If you’re not looking to purchase anything new, then stick to the basic essentials which are:
- Warm clothing like sweaters, socks, gloves, and a hat.
- Cold weather bedding like a wool blanket.
- Warm or hot drinks to keep you hydrated.

Jake is a freelance writer from Pennsylvania who enjoys writing about science and sports. When he’s not writing for Temperature Master, he can be found watching the NFL or playing basketball with his friends.