system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do sometimes soft blankets feel warm and sheets feel cold in the same condition?
gpt
Think of it this way, a blanket doesn't make you warm. It stops the heat from leaving. 

Your body warms the air around you. A fuzzy or fluffy blanket is harder for the air to escape than a sheet, so there's more time for your body to heat it up, and it takes longer for it to float away, so you have warmer air around your body.

This is the opposite of what a fan does. A fan doesn't make the air cooler, it just blows away the warm air that's around you.