A warm, dry and comfortable sleep is not only refreshing and relaxing after an adventurous day outdoors, it’s a critical aspect of staying healthy and safe as well. Staying warm involves more than just being cocooned in a bag full of synthetic down feathers. Your sleeping platform and what you are wearing as you crawl inside your bag can all affect how warm you’ll stay throughout the night.
Here’s a look at ways to stay warm – starting from the ground up:
Sleeping base/floor– insulating yourself from the cold/wet ground is fundamentally the most important aspect of a good sleeping foundation. Comfort runs a close second!
Outdoors, insulating yourself from the cold/wet ground can be minimized by a thick layer of natural insulators such as leaves, grasses, or evergreen boughs. A framework of logs can be used to define the space and confine your pile of insulation. Topping this with a tarp or space blanket (silver side up) protects you from ground moisture and in a small way, reflects heat back to your body.
You might consider pitching your tent over a pile of leaves to give yourself a bit of a floor cushion. Also, laying down your space blanket inside the tent works as both extra protection against ground moisture, and serves as a heat reflector as well.
Sleeping Pads – Air mattresses can keep you above ground moisture, but also allows the surrounding cold air to lower the temperature of the air in the mattress chambers as well. So you are provided comfort through air support but not necessarily protected agains the cold. Mattresses that incorporate a synthetic down-like fiber filling provide an air mattress cushioning effect with the added benefits of down and similar fibers holding warmth in their air spaces.
Closed-cell pads are typically shorter and thinner and don’t offer near the comfort of a thicker air cushioned pad. They are, however, much better at providing insulation against the cold than are air mattresses. The option then becomes using the air mattress for the comfort and positioning a closed-cell pad on top to insulate you from the cold air in the mattress and your surroundings.
Sleeping Bag – Even the most luxurious sleeping bag needs help when the air temperature drops below the rating range of that specific bag. It’s a good idea to always bring a bag rated for at least 10 degrees colder than those temperatures you expect to encounter. You can optimize the warmth of your “sleep system” in a number of ways:
- Buy quality insulated bags with correct fit (too snug and it can constrict blood flow making you colder); collared zipper channels and adjustable, vented hoods
- Consider a bag liner (flannel sheets work well)—it can provide several degrees of warmth. They are also easily removed to air/dry bag out each day and they help reduce body oil soiling the inner bag
- Wear “pajamas” such as under-layer pants/shirt or farmer johns; wear a stocking cap
- Keep feet warm with wool socks
- Fill a water bottle with hot water or add hot rocks to extra socks and place at bottom of sleeping bag when settling in for the night
Your sleeping bag is a third level of shelter (after your skin and your clothing), so it’s critical that you use the right bag for the right environment and take measures to ensure that you get the most out of your bag’s ability to keep you warm and dry and cozy!