What regulates your body temperature?
Thermostat of the body is present in Hypothalamus part of brain.
Our body temperature remains amazingly stable in all livable climatic conditions. There are several mechanisms by which this could be achieved.
For example, conservation of body heat in cold condition is achieved by: vasoconstriction of blood vessels supplying blood in skin and terminal parts of body (like finger tips, nose tip, etc.). As a result perspiration and sweating almost cease. Shivering also helps in generating more of body heat. Metablolic rate also increases in response to secretion of thyroxine.