The demon plant otherwise known as giant hogweed isn’t physically hot, and doesn’t even contain a chemical that causes an immediate burn. It hurts you in a more sinister way. Giant hogweed releases a sap containing chemicals called furanocoumarins, which sensitize human skin (as well as that of many other animals) to sunlight. And we’re not just talking about a little extra redness if you stay out in the sun all day—we’re talking probably the worst sunburn you’ve had in your life (seriously, go look at those pictures). The reaction depends a lot on how much sap you get on your skin, how much you’re sweating, and how hot the day is (moisture and heat make it worse). Within 15 to 30 minutes of contact with the plant, you’ll start to feel the reaction, and then you’ll keep burning for another couple hours. The burns can be so severe that it takes months for affected skin to heal fully.