The scrotum reacts to temperature. When it is cold, the scrotum shrinks, pulling the testes against the body to keep them warm. When it is hot, the scrotum relaxes, lowering the testes away from the body. This contractile ability of the scrotum can either raise or lower the temperature of the testes by a few degrees, ensuring that the optimum temperature for sperm production is maintained.
The central nervous system is responsible for controlling the temperature of the human body. The central nervous system is made of two parts: brain and spinal cord. The hypothalamus which is a small part of the brain controls the temperature of the body
