Your kidding right? You could die sitting on the couch watching the game. Using any tools, equipment, etc means using common sense and safety. Never wear loose fitting clothing, know where the on/off switch is in case of emergency, eye protection is a must.
If used incorrectly a lathe or mill could seriously hurt you but if you use your common sense and follow the manufacturers safety guidelines you should be ok. I never wear a vest or a helmet but do wear safetly glasses.
Mike