When males reach a certain age, the body begins the process of puberty. how does the body control this process?

In girls, the main hormone that starts to be highly expressed is estrogen and progesterone while in males, testosterone. This is triggered by the hypothalamus that releases gonadotrophic-releasing hormones (GnRH).  GnRH then triggers the pituitary to release LH (Luteinizing Hormone ) and FSH (Follicle Stimulating Hormone) that act on the gonads (ovaries in females and testis in male)

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.