Question

Why it is that evaporation causes cooling,but boiling causes heating?

Answer 1

During evaporation, particles which have a high kinetic energy come out of the body by gaining heat due to which there is a cooling effect on the particle of the body itself. that is why, evaporation causes cooling. For example: sweating 

Answer 2

In evaporation due to internal heat, kinetic energy of molecules increases and they come to the top and take out that heat with them when they evaporate thus causes cooling 
in boiling as heat is given to the molecules so their kinetic energy increases and they start vibrating with great energy and thus causes heating