What Causes Heat Intolerance?
Most people don’t like extreme heat, but you might find that you’re always uncomfortable in hot weather if you have heat intolerance. Heat intolerance is also referred to as hypersensitivity to heat.
When you have heat intolerance, it’s often because your body isn’t regulating its temperature properly. Your body regulates its temperature by maintaining a delicate balance between hot and cold. The hypothalamus is a part of the brain that regulates your body’s temperature. When you get too hot, your hypothalamus sends a signal through your nerves to your skin, telling it to increase sweat production. When sweat evaporates off of your skin, it cools your body down.
https://www.healthline.com/symptom/heat-intolerance
