Eating very spicy food can make you sweat a lot. You might think, "Why am I sweating so much?" while your neighbor looks calm. Actually, your ability to handle spicy food is determined by genetic differences. The number of pain sensors on your tongue decides your tolerance to spiciness.

The real nature of spiciness is not about taste but about pain. According to Professor Yamada from the National Institute of Sensory Nerve Research, when you eat spicy food, your brain receives a "fire alarm." For example, the main component in chili peppers, capsaicin, stimulates the same pain nerves as a burn over 43 degrees Celsius. This is because the "pain warning system," which evolved to protect humans, is fooled by spicy substances.