That's the FIRST thing we were taught in my one and only course in machine shop. It was a 9 week course. Accidents DO happen but in this instance it appears that that bulky sweater was the culprit.IMO if you can't afford to heat the shop you got one of 2 choices,either don't run the machine OR take off the bulky shit ,roll up your sleeves and shiver your ass off while running it. NEVER run a machine wearing anything loose fitting that might snag and suck you into tragedy.