Question

How woolen clothes have a layer of air between two layers of cloth

Answer 1

During winters wearing more layers of clothing keeps us warmer because there are small pores inside the clothing thus it traps air as air is a bad conductor /insulator of heat it does not let heat escape from the clothing . Thus wearing more layers of clothing keeps us warmer than just wearing a thick piece of clothing , woolen clothes are thick so it traps air in between them..