Keeping warm at winter camp | Assessment Resource Banks

This task is about insulation against heat loss.

Question

a) At a school camp, on chilly nights, everybody slept in their sleeping bags.

What is the main way a sleeping bag helps to keep a person warm?

- Layers of special fibres in the bag create heat.
- The person's body heat is kept inside the bag.
- The outer layer of the bag attracts heat from the night air.
- The bag's outer layer keeps the cold air out.

b) On a cold day, why do several layers of thinner wool clothing act as a better insulator than a big, heavy, woollen jersey?

- The heavy clothing causes sweating and the body loses heat rapidly.
- Thin, wool clothing is more comfortable and is easier to move in.
- Thick clothing, although it is a good insulator, does not allow the skin to "breathe".
- Air trapped between the layers of clothing acts as an insulator and reduces heat loss.