Final answer:
The testes are located in the scrotum to maintain a temperature suitable for sperm production, which is a few degrees cooler than the body's core temperature, critical for sperm viability.
Step-by-step explanation:
The paired oval testes lie in the scrotum outside the abdominopelvic cavity, where they are kept slightly cooler than body temperature. The testes, being positioned in the scrotum outside the body, allows for the temperature of the sperm to be maintained at a few degrees lower than body temperature, which is necessary for the stability of these reproductive cells.
Sperm production occurs within the seminiferous tubules of the testes and is very sensitive to temperature changes. This may be the most important reason the testes are located outside the body in the scrotum. If the testes do not descend from the abdominal cavity during fetal development, a condition known as cryptorchidism may occur, potentially leading to infertility due to improper sperm temperature regulation.