Explain to the group that because the ground is so cold, you’ve provided a nice cozy blanket for them to stand on.
Spread the blanket on the ground or floor.
Ask the whole group to get on it so that no body parts are touching the ground off the blanket.
Once the group successful completes standing on the blanket, advise them that you’ve received a report that another group needs half of their blanket to keep their feet warm, too. Ask them get off and fold blanket in half.
Repeat the above process as many times as possible. Each time you fold the blanket, the group will need to be more creative (and cozy) to sucessfully stan on the blanket.