Good point Dude. If the "shield" has air flow directly over it it helps heat distribution and keeps the "shield" cooler. Burning the tobacco in the kiln is a No-No. LOLBe careful if your bulb is facing up and your tobacco is above it. If any tobacco were to fall onto the bulb you'd have yourself a nice fire in no time. I use a light bulb screwed into a metal dome shaped receptacle. If any leaf were to fall it would (in theory) just slide down the side and onto the floor.