This hat — made from cotten fiber, silver and copper — will help reduce your brain's exposure to EMF. LessEMF also sells shirts and cell phone covers to accomplish the same thing. The shielding comes at a price, though. When you reduce the radiation coming from a cell phone, you also reduce the signal strength and sound quality. Call me crazy, but if you have to shield your cell phone such that it doesn't work anymore, maybe you're better off not carrying one at all. Although the jury may still be out on the effects of EMF exposure, the hats may also help keep the government mind-readers at bay. At least that's why I'm buying one.