It produces heat as a waste product which can make a rise in our body temperature. In order to maintain homeostasis, the blood vessels in our skin dilate to allow more blood flow to the surface of our body removing heat and causing sweat glands in the skin to release more sweat. The evaporation of sweat and breathing out warm air also help to cool our body which will help to maintain a constant temperature.
In relation to heart rate and exercise, our cardiovascular system plays a vital role in delivering blood and nutrients to our muscles controlling the body temperature. While we exercise, the muscles will need more oxygen which will cause increase in the amount of blood because our heart will be pumping and moving that blood from passive organs to active muscles. Hormones will release to give sign for our heart rate to increase so that more oxygenated blood and nutrients will be transported to where we need them the