Skin temperature is controlled by a complex interplay of internal and external factors, primarily regulated by the hypothalamus, a region in the brain.
The hypothalamus acts like a thermostat, constantly monitoring your body's internal temperature and comparing it to a set point (around 98.6 degrees Fahrenheit). When your body temperature deviates from this set point, the hypothalamus triggers mechanisms to restore balance. These mechanisms include:
- Blood vessel dilation: When you're hot, blood vessels in the skin dilate (widen), allowing more blood to flow near the surface, which helps dissipate heat.
- Sweating: As sweat evaporates from the skin, it cools the body.
- Shivering: When you're cold, the hypothalamus sends signals to your muscles to contract involuntarily, causing shivering, which generates heat.
- Blood vessel constriction: When you're cold, blood vessels in the skin constrict (narrow), reducing blood flow to the surface and minimizing heat loss.
While the hypothalamus is the primary regulator, the skin itself also plays a role in thermoregulation. The blood vessels in the dermis help distribute heat throughout the body, and the skin's surface acts as a barrier to help regulate heat loss.
Additionally, external factors like environmental temperature, clothing, and physical activity also influence skin temperature.
