FFS. Only on ******e can such a simple thing run on to 2 pages: The pitot heater is supposed to keep your ASI working. It stops you losing control and crashing. alternater is fairly far down the list compared to ASI. Aviate Navigate Communicate etc. Wet and cold=Ice= ASI might not work: so check it goes warm when you want it to in the pre flight checks. touch it ( It takes about a minute before anything happens), highly unlikely to fatally burn yourself unless you get seriously distracted. Then it gets slightly warm. Turn it off before you drain the battery. Go Flying. Turn it on if you might go into some cold cloudy stuff. Use your superior flying skills to avoid such complications. Live another day to speak s*it on pprroone private flying section.