Because the skin controls your body temp and if your skin is burned , it messes with the temp making your body colder which leads them to become hypothermic
1) painful intercourse
2) Mood swings
3) Breast tenderness
4) Increases in UTIs
5) migraines
Let's start with what we now, physical activity, physical meaning related to the body motion. If you are walking, you are physically walking and if you are running you are physically doing so. So id one is doing physical activity for the purpose of getting fit, then it is called exercise.