Snow and ice are cold. Its hard to imagine that a house made of ice and snow can actually keep anyone warm, yet we all know that the Eskimos stay nice and toasty in their frozen igloos.
How do these Arctic dwellers prevent frostbite when living in sub-zero temperatures in their homes made of the same ice and snow?

The human body’s temperature is on average 98.6 degrees Farenheit, no matter what the outside temperature. Our body’s metabolic system heats up our bodies using the energy from calories burnt. We are constantly radiating energy and losing it and our bodies are constantly warming ourselves up again.
When the outside temperature is too low, our body loses heat faster than it regains it and we are in danger of getting dangerously cold.

The way that Eskimos manage to retain warmth in the frosty Actic in their igloos is this: Heat is always escaping, diffusing from warmer areas to colder areas. By insulating themselves with bricks of ice, the heat from their body and from fires lit within does not escape as quickly. The air inside igloos warms up because the heat is not able to diffuse speedily because of the insulation.

This blog is not a science blog. The reason I explained about Eskimos and igloos is because we can utilize the same methods as they do to keep ourselves warm on wintery nights.

As our bodies diffuse heat into the surrounding air, if we are able to insulate that heat and get the warmth to remain near our bodies, we do not end up needing to heat the surrounding air as much via heaters. Warm pajamas and down blankets work as good insulators to retain our body heat in the air immediately next to us.

However much heat one body gives off, two bodies give off twice as much heat, three bodies give off thrice as much heat, etc.

When people sleep next to each other and under the same insulating blanket, there is less of a need for heating.

There are many ways you can utilize this method to keep yourselves warm while sleeping. Husbands and wives could sleep together under the same blanket. Mothers and babies can co-sleep together and share each other’s body heat. Siblings can share a bed and warm each other up.
It is a new “invention” for each person to have their own sleeping space. In past times, children would sleep in their parents beds until they reach a certain age; once they got older, they shared beds with their siblings. I’ll bet you that one of the big reasons for this sleeping method, aside for lack of space, was because it lessened the need to heating the home at night.
If it is feasible to get two of more family members to sleep under the same blanket, you’ll be lessening the need for heating in your home.

If discomfort or other reasons preclude you from using the bed-sharing method of keeping warm at night, there is an alternative method of warming that involves heat diffused from non human sources.
Hot water bottles are great ways of keeping warmth beneath your covers without necessitating heating the whole room. Easy, simple, and cheap.
Boiling a kettle of water costs very little money. You pour the boiling water into the hot water bottle and the rubber of the hot water bottle works as an insulator. For many hours, heat diffuses slowly through the rubber, warming up the air under the covers, the air close to your skin.
Some hot water bottles come with a cloth insulator, which makes them diffuse the heat even more slowly. Just look how cute this one is. Don’t you just want to cuddle up with it in your bed?
A hot water bottle can easily continue warming from when you go to sleep until when you wake in the morning.
In my experience, the best place to keep a hot water bottle is under my blanket, near my stomach. When it cools down somewhat, I put it touching my skin.
Use more than one hot water bottle for an either greater effect.

Whether you decide to use body heat or hot water heat, remember the trick of the Eskimos- proper insulation can keep the warm within, even on the coldest of nights.