Summary
Sweating, shivering and blood vessel changes keep core temperature near 37 degrees Celsius.
In depth
Hypothalamus is the thermostat. Heat loss: sweating, vasodilation, panting. Heat conservation: vasoconstriction, shivering, hair erection and brown fat in infants. Fever is a raised set point.
Heat is generated by metabolism and shivering. Blood vessels in the skin adjust heat loss. Heat stroke occurs if regulation fails.
Example: fever is regulated by a raised set point, not failure.
Core temperature is about 36.5 to 37.5 degrees. Heat is produced by metabolism (liver, muscle) and exchanged by radiation (about 60 percent at rest), conduction, convection and evaporation (the only way when ambient temperature exceeds skin temperature). Cold activates sympathetic vasoconstriction, shivering (up to 5 times resting heat production), brown fat thermogenesis in infants and piloerection (little effect in humans). Heat triggers vasodilation and sweating (up to 1 to 2 litres per hour).
Heat exhaustion and heatstroke (core above 40 degrees, with confusion) are medical emergencies; hypothermia occurs below 35 degrees. Babies and elderly are vulnerable. Humans are well adapted to heat via sweating and hairlessness, which helps endurance running. Acclimatisation over 1 to 2 weeks raises sweat rate and lowers its salt content.
Key idea: the hypothalamus compares body temperature with a set point, and effectors correct deviations.
Frequently asked questions
What is Thermoregulation?
Sweating, shivering and blood vessel changes keep core temperature near 37 degrees Celsius.
Which area of biology covers Thermoregulation, and how advanced is it?
Thermoregulation is one of the 51 topics in Human Physiology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Exercise Adaptations, Exercise Physiology, Blood Glucose Regulation.
Can you give an example of Thermoregulation?
Hypothermia occurs below 35 °C.
What should I learn before Thermoregulation?
Work through the Beginner topics in Human Physiology first, such as Homeostasis, Tissues and Organs, Skeletal System, then return to Thermoregulation. Intermediate topics assume the Beginner vocabulary.
What topics are related to Thermoregulation?
The closest topics to Thermoregulation are Exercise Adaptations, Exercise Physiology, Blood Glucose Regulation, Energy Balance and Metabolism. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Thermoregulation?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Thermoregulation. To practise the whole of Human Physiology, use the Human Physiology quiz.
How is Thermoregulation different from Exercise Adaptations?
Thermoregulation: Sweating, shivering and blood vessel changes keep core temperature near 37 degrees Celsius. Exercise Adaptations: Training increases stroke volume, capillary density and mitochondrial content in muscle. Read both side by side and note what each one explains.
How should I study Thermoregulation step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Exercise Adaptations and explain the difference aloud. Finally, take the Human Physiology quiz and come back to this page for any question you miss.