We should wear light colored cotton clothes in hot summer to keep us cool and comfortable. Light colour is preferred because it reflects heat. Because of our body mechanism we tend to perspire more during summers. This helps to keep our body cool. During evaporation, the particles at the surface of the liquid gain energy from the surroundings or body surface and change into vapour. The heat energy equal to the latent heat of vaporization is absorbed from the body leaving the body cool. Cotton, being a good absorber of water helps in absorbing the sweat and exposing it to the atmosphere and makes evaporation easy.