Final answer:
The testes are located in the scrotum outside the body to regulate temperature for sperm production.
Step-by-step explanation:
The testes are located in the scrotum outside the body because sperm production is very sensitive to temperature.
The scrotum regulates its internal temperature by contracting its muscles.
When the temperature inside the scrotum becomes too low, the muscles contract and pull the scrotum closer to the body to warm up.
On the other hand, when the temperature inside the scrotum becomes too high, the muscles relax and allow the scrotum to move away from the body to cool down.