Thermal Bag

Wondrous item, uncommon

A thermal bag is a piece of emergency survival equipment used to protect an individual from subzero temperatures.

The bag comes in a tiny canister about the size of a human’s thumb. When the seal is popped, the thermal bag rapidly expands forming a full sized sleeping bag large enough to fit one medium-sized creatures. Chemicals within the bag’s lining react to the expansion producing heat and warming the inside temperature to a comfortable 85ºF.

Once opened, the bag remains hot 24 hours, after which point it becomes an ordinary insulated sleeping bag safe to use in any non-subzero temperature. Unfortunately, once released from the carrying canister, the expanded bag remains at full size and cannot be returned to the canister.