What role does the skin play in the regulation of body temperature?

Explanation:

Skin plays an important role in regulating the body temperature. It releases the body heat by producing sweat. The sweat is produced by the sweat glands and it comes over the surface of skin from where it get evaporated. This process provides cooling to the body.

Also the skin is a protective layer around the fat which regulates the insulation process which prevents the loss of heat from the body in winters.

so whats the answer

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.