Capsaicin is the chemical compound that makes chili peppers taste hot. It is a skin irritant to humans (and pets), and can cause a burning sensation if applied to the skin.

Capsaicin, or more commonly, ingredients containing high amounts of capsaicin, are widely used as flavorings in spicy cuisines. All members of the pepper family that are hot have high levels of this compound. Hot sauces such as hot salsa and Tabasco are high in capsaicin, and you can easily burn your mouth eating spicy foods if you are not careful.

Drinking water to quell the heat caused by too much capsaicin in your meal is ineffective, since capsaicin is not water-soluable. The most effective antidotes are those containing fat and/or sugar. Capsaicin is fat-soluble, and sugar will block the receptors that are reacting with it, so if you're really suffering, go for cheese, ice cream instead of ice water or beer. Capsaicin will bond with the fat in the food end your pain.

Capsaicin is most recently making its heat felt in topical analgesics. Sports creams and muscle rubs that seem to heat the skin often now contain capsaicin either in lieu of, or in addition to, the more traditional menthol. Some say that capsaicin is showing some promise in treating arthritis symptoms; it seems over time to have a cumulative effect on the pain, by overloading the nerves and lessening their ability to transmit pain signals to the brain. Many of the new patches that adhere to the skin and are placed over the painful area are now using capsaicin to effect their promised pain relief.

Capsaicin is also making news in the diet and nutritional fields. Some studies show that a diet high in chilis or other capsaicin-laden foods can raise your base metabolism, the rate at which your body burns fat while at rest. There are also studies claiming Capsaicin both lowers LDLs, or 'bad cholesterols', but raises HDLs, or 'good cholesterols' too.

With all that going for it, consider yourself lucky if you like spicy cuisines, and help yourself to as much capsaicin-generated heat as your mouth can stand.