Not really. It's minimal plants can grow up to glass. There is very little heat. It is air cooled supposedly so you can vent towards the canopy. The light is not very warm. You can comfortably rest the glass on your skin. Only reason glass is there is to stop the uvc from killing everything and giving you skin cancer. They tested it w/out glass and it sterilized everything (molds & probobaly everything else) lol. You can add them to flowering lights and they will cover more area than when they are used for growth. They don't really add heat to the crop. Just sunlight minus heat. It is so close to the real spectrum of the sun. Instead of other types of lights its a point light source and constant. There is no flickering or frequency band like hps. I hope I explained that part right. It makes for thicker leaves and makes for a more healthy plant.