Capsaicin, the primary spicy chemical in peppers, causes your body to respond as if it were in a hot environment. Capsaicin activates certain chemical receptors inside your body to cause a reflexive cooling response.
According to an Arizona University article entitled "The Capsaicin Receptor; A Pepper's Pathway to Pain," capsaicin is a molecule found in chili peppers that causes the spicy taste. The body also has a capsaicin receptor found on certain nerves that are heat-sensitive. When activated, these nerves send signals to the spinal cord and brain to send a perception of heat-related pain. The brain responds by triggering chemical reactions to cause cooling of the body, such as a sweat response.
Why You Sweat
Because capsaicin sends signals to your brain of overheating, your brain attempts to cool your body through certain mechanisms. Specifically, the hypothalamus is the thermoregulation center of the body, states USATODAY.com. This area of the brain activates the millions of sweat glands in the body to start producing sweat following capsaicin ingestion. Sweat is released from the glands and eventually evaporates to cool the body. However, because the temperature in the environment may be cool, sweat may take longer to evaporate.
Why Flushing Occurs
In addition to sweating after eating spicy foods, you may also begin to flush. According to USATODAY.com, this occurs because the hypothalamus sends dilation signals to the blood vessels underneath the skin. Dilation of these blood vessels allows warm blood to dissipate heat, which results in cooling of the body. Therefore, flushing is another inappropriate cooling response to capsaicin ingestion, which may occur in a cool environment.
Neutralizing Capsaicin Effects
Neutralizing the effects of capsaicin is important in controlling the sweat response. Drinking water may provide temporary relief, but because capsaicin is not soluble in water, it does not cause lasting relief. However, according to ChipotleChiles.com, capsaicin is soluble in alcohol and fat. Because it would take strong alcohol to relieve capsaicin's effects, drinking a fatty substance, such a milk, can help relieve symptoms.