Final answer:
The receptor of the sympathetic nervous system that regulates heat loss through the skin is the thermoreceptor.
Step-by-step explanation:
The receptor of the sympathetic nervous system that regulates heat loss through the skin is the thermoreceptor. Thermoreceptors are specialized sensory receptors that detect changes in temperature. When the body becomes too warm, thermoreceptors in the skin send signals to the sympathetic nervous system to initiate responses that promote heat loss.