"In the event of a disaster, such as an earthquake or flood, The drinking water system frequently becomes contaminated.
Therefore you need to shut off the intake valve to your water heater.
Then your water heater becomes an emergency drinking water tank."
Actually, you shouldn't always wear those. Like when working a lathe for example.
If your glove snaps on you loose your hand (if your lucky, with a lathe it can go real bad real fast).
You beat me to it, that and running a belt grinder are the times I don't wear gloves unless I absolutely have to (grinding metal can get hot). I also make sure not to have long sleeves (nothing much past my elbow) or jewelry of any kind, I've heard too many horror stories from older guys that taught me...
Also never wear them while using a drill press for similar reasons to the lathe.