The same nerve receptor that responds to the green paste on your sushi plate is activated by car exhaust, the smoke of a wildfire, tear gas and other chemical irritants. iStockphoto hide caption

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Ready to feel the burn? Check out our tips for tiptoeing into hot sauce. John Kuntz/The Plain Dealer/Landov hide caption

itoggle caption John Kuntz/The Plain Dealer/Landov

Jasjit Kaur Singh, an Indian chef, cooks kaala channa, a traditional spicy Sikh dish. A psychologist says that children who grow up in cultures with lots of spicy food are taught to like spice early on. Richard Lautens/Toronto Star via Getty Images hide caption

itoggle caption Richard Lautens/Toronto Star via Getty Images