Largely the skin but also the lungs and the kidneys.
Sweat glands
An organ in some animals that allows for the regulation of body temperature, such as a countercurrent heat exchanger in some fish.
The liver is often considered the organ that generates the most heat in the body due to its role in metabolism and energy production. Additionally, muscle tissue can also generate significant heat during activity.
When you have a fever, the temperature of your entire body is raised. Perspiration(sweating) is your body's natural reaction to heat, because moisture evaporating from your body allows heat to leave.
skin
The organ that excretes Urea compounds are the kidneys, BUT they do not excrete HEAT. No organ of the human body EXCRETES heat.
there is no organ,it is the nerve cell that tells us what is hot and cold.it sends signals to your brain.
the nervous system
The primary excretory organ that helps regulate body heat is the skin. Through processes like sweating, the skin releases heat from the body to cool it down. Sweat glands in the skin produce sweat, which evaporates from the skin's surface, taking heat with it and helping to maintain the body's temperature.
It allows body to lose heat by sweating
It helps the body remove heat through sweating, and it also allows it to use water as an energy source.
That would be your skin. Your skin is in fact the largest organ of the body, and covers everything internally, and regulates heat.