Tonight I zapped like I normally do, but a couple of things happened that were different. Everytime I would stop zapping, I would break out in a sweat. ( I normally zap 7-10 minutes, turn the zapper off for 20-30 minutes and do it again. I normally do this 3-4 times.) This is the first time I have ever sweated like this and I have been zapping for a long time now. I even developed a headache and I never have headaches. I noticed tonight that every time I turned the zapper on, I would feel more of a tingling sensation than usual. Also, I have a red mark on my left arm from the zapper and that's never happened before. Any ideas out there? I didn't change batteries, so that's not it.