Question

If warm blooded animals can not change their temperature according to the atmospheric temperature (humans are also warm blooded animals )
then ,
when people enter a swimming pool intially they feel it to be cool but later they feel it to be hot .why?

Answer 1

So-called warm-blooded animals control the temperatue of their body at quite a high level. This ability is called endothermy. All mammals and birds are endotherms (homeotherms or homoiotherms). The basic source of the heat is chemical energy from the body's metabolism . they have a number of temperature-control devices:

1. When they are cold they can do things to make themselves warmer. For example, they "shiver", or shake, or run about, or move into a warmer place. This is because all movement by animals creates heat from the chemical reaction of respi.ration So polar bears do not freeze because their metabolism produces heat, and movement produces more heat. During hibernation bears exist several degrees lower that they do in active life. Of course, warm-blooded animals have thermal insulation: hair, feathers, or in water blubber(thick fat). These adaptations help keep heat energy inside the animal.
2. When they are warm they sweat to become cooler, or pant or open their feathers, or move to a less hot place and lie down.

When people enter swimming pool the metabolism of body help to change the temperature of the body.