What’s causing leaves to curl up and fold?

Try raising your lamp.. It's usually heat stress when leaves curl like that. - Your thermometer is to the side of the lamp, so it doesn't catch how hot it actually is beneath it, but rather that temp of the air around.. There can be a big difference between heat below the lamp, and general heat in the tent. - I got 2 thermometers going in my tent. One placed on top of the soil, directly below the lamp, and one place to the side. They say two very different temps.