Final answer:
A thermostat is a device used in control systems, such as the human body, to maintain a steady temperature and achieve homeostasis.
Step-by-step explanation:
A thermostat is a device used in control systems to maintain a steady temperature. In living systems, such as the human body, the hypothalamus acts as a thermostat to regulate core temperature. If the temperature exceeds the set point, the body initiates processes to cool down, while if the temperature drops below the set point, it activates mechanisms to generate heat. This helps maintain homeostasis, a state of equilibrium, in the body.