To keep warm and comfortable in extremely cold temperatures, down filled sleeping bags were issued at Scott Base that are designed so that there was an outer bag and an optional inner bag that could be zipped together to form a single sleeping bag. Most field workers opted for the inner and outer bag combination. This bedding was carried in a yellow carryall bag along with a Thermarest sleeping pad containing a core of closed cell foam.
In the field, the Thermarest pad was unrolled and a cap opened to allow air to enter the mattress, although the pad could also be orally inflated, depending on requirements. The Thermarest mattress insulated the occupant from the frozen ground with a combination of air and closed cell foam, even if the pad was punctured. This is very important as being elevated off the ground prevents the loss of a lot of heat.
The sleeping bag with its multiple layers and down filling combined with the Thermarest mattress allowed researchers to get a good night’s sleep in most conditions. On a fine day it can sometimes even become too warm. To prolong the life of these expensive down-filled sleeping bags, an inner liner and an external sleeping bag cover were to be used at all times.