Road Tripping During The Winter? How To Stay Warm When You're Sleeping In Your Car

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A road trip that's long enough for a couple overnighters calls for a little extra attention to ensure you're comfortable camping out in your car, but there's a huge difference between doing this in winter compared with just about any other time of year. In winter, warmth is the most important factor, since your car, with the heater and engine off, won't retain the warmth it did while the car was running. If sleeping in your car is allowed at rest stops in your state, staying warm overnight in your car comes down to bringing the right bedding materials, plus some extra supplies to keep the air in the car warmer, too. 

A sleeping bag rated for cold weather can keep your toes and everything else toasty on a cold winter night. Keeping warm clothing on hand helps too; this could even mean outerwear such as a warm hat and gloves or mittens. If you have loads of space, as may be the case with a van or SUV, you have room to treat it a little bit more like a tent-camping experience, decking it out with appropriate supplies such as an air mattress. No matter what vehicle you have, the right window coverings will help your ride retain warmth, too. Properly fitted, insulated sunshades helps trap warm air, and provide privacy. Even though you're trying to stay warm, leaving the windows open just a little provides fresh air and reduces condensation. It's one of those must-know tips for safely sleeping in your car, and will help keep your window interiors from freezing and cooling the whole space.

The simplest thing to pack for added warmth overnight is a sleeping bag rated for the cold. Look for a bag rated for 20 degrees Fahrenheit or below, like the Teton Celsius series. A nice down comforter is helpful and doubles as a privacy screen when it's time to change clothes near the car. An insulated sleeping pad such as the Gear Doctors Oxylus insulated foam sleeping pad makes things both comfier and warmer (self-inflating will save space). Wearing warm socks plus thermal underwear will also help you retain heat overnight, as will a hat and gloves. Make sure outer layers are easy to open or remove in case you feel too hot. Boiling or near-boiling water in a hot water bottle will keep you cozy most of the night. Fill it about two-thirds full so your body weight doesn't pop the bottle if you should roll onto it. 

To keep the air in your car warmer longer, place reflective insulating sun shades on the inside of your windows, such as any of those made by WeatherTech. These fit specific vehicle makes and models. You could also go the DIY route using something such as Reflectix bubble pack insulation. It can be cut to size and taped on your windows from the inside. Both options help the car retain heat while offering you some welcome privacy as you sleep.

Remember to bring an external power bank or charger for phones and other tech, so you don't drain your car's battery overnight. And whatever you do to keep warm, never use any sort of gas or flame heater, even portable camp heaters. Not only is it a fire hazard, they can emit dangerous carbon monoxide, filling your enclosed car while you sleep.