Why do we sweat and feel hot after running or exercising?

Explanation

The food we eat gets slowly oxidised in the body. The carbohydrates and fats in the body are combustible materials that are oxidised to liberate heat and energy. After running or exercising one feels hot and sweaty because energy has been consumed releasing heat. The food which we had consumed earlier and stored in the body as fuel has been oxidised liberating energy causing a rise in body temperature which results in sweating.
`underset"(Carbohydrate)"(C_6H_12O_6) + 6O_2 to 6CO_2 + 6H_2O` + Heat energy