Biology.
Homeostasis
Have you ever wondered why your temperature increases or decrease? Why your heart rate goes faster or slower? Why your heart beats harder or softer? Well I never had asked but then, I did my biology project and I answer all those questions, some of you could have. First of all we measure our temperature and our pulse. Then we run like for 3 minutes, immediately we stopped, we measure again our temperature and our pulse. Our pulse in all cases increases, so our heart was beating faster.
And the logic for most of us was that the temperature will increase too, but we get a surprise and in some people, like me, the temperature after I run was lower than before, so we studied that result and we get the conclusion that my temperature was lower because when I started running my internal temperature started to increase so in fact to do homeostasis my body started to sweat and that sweating was the reason of why my external temperature was lower.