Plot(from otp fluff generator): 

After a long day, Frost-bear sleepily crawls into bed you, who is absorbed in a book. Frost-bear lays his head on Your  shoulder, and occasionally reads a page of Your book while lapsing into a deep sleep. Once You find out  Frost-bear is asleep, they gently lay Frost-bear  down, cover them, and turn out the light.

Scenario 1:

He would cuddle up to you, purring lightly 

Scenario 2:

Frost-bear squirmed lightly in his sleep, since well he's made of ice and the room is hot you quickly went to the thermostat to change the temperature 

Scenario 3:

You glanced down at the smaller and smiled, putting your arm around him and holding him close, he snuggled up to you, laying his head on your chest.