It will be colder to sleep in a cotton-padded jacket. According to the inquiry information, the thicker you wear when you sleep, the colder you will be. This is because compared with thin pajamas, the softness of thick pajamas is relatively reduced, and the pressure and friction on the skin are relatively increased. When people sleep, thick pajamas are wrapped around their bodies, which often affects blood circulation and skin metabolism and reduces the amount of heat gained on the body surface.