Question

why do the doctors advice to put strips of wet cloth on forehead of a a person having high fever ?

Answer 1

This is because wet strips absorb the heat from the body regulating the body temperature

Answer 2

When a person has fever his body temperature becomes more than the normal body temperature. If we put strips of wet cloth on the forehead of a person suffering from high fever, the water evaporates taking heat from the body, creating a cooling effect. Thus, moist strips will lower his body temperature.