Question

We feel cool after doing vigorous exercise , Why ?

Answer 1

When we perform vigorous exercise, we generally sweat.
Sweat formed on the skin evaporates into the atmosphere by absorbing heat energy from our body.
As evaporation causes cooling effect. Hence our body temperature reduces and we fool cool.

Answer 2

When we perform vigorous exercise, body temperature increases. To get back the normal temperature of the body, it sweats, gradually heart beat slows down to normal. Respiration rate also slows down to normal. The sweat evaporates giving a cooling effect to the body. Blood vessels dilate during exercise to release the heat produced and constrict after exercise to give cooling effect.