Question

in winter a cotton shirt cannot keep us as warm as a woollen sweater .why?

Answer 1

Cotton shirts are very thin and don't have space in which air can get trapped inside.So, because of cotton shirts heat comes out of our body and we don't feel warm.Woollen shirts keep us warm during winter season as wool is a poor conductor of heat and it has air trapped in between the fibres so we feel warm.

Answer 2

Because the wool absorbs moisture but keeps warm but cotton doesn't it make us feel cool by absorbing sweat