When we on our fan , air molecules kinetic energy increases and temperature must increase then why we feel cool

When you are feeling hot and your whole body is sweating with water all over ,you generally prefer to sit under a fan. This helps to evaporate water quickly as the 'fan air' temperature is less than that of the human body and thus better heat transfer occurs from our body to the environment.
This faster rate of evaportion causes you to feel cool.