1. Hypothalamus is thermoregulatory centre in brain. This detects increase in temperature (above 37 degrees Celsius) and is activated.2. Hypothalamus causes vasodilation of skin capillaries, which causes heat loss by radiation through the skin3. Hypothalamus causes relaxation of erector muscle. This causes hair to lie flat, so skin can cool4. Hypothalamus stimulates sweat glands to secrete sweat, which causes heat loss by evaporation of sweat from the skin5. This process is an example of negative feedback