I never used to. never got stung (that I know of)...Some people are a bit more sensitive than others (like bee stings). I have seen people get stung from things that don't cause me problems, but cause "them" a great deal of grief. The flip side is introducing something into the tank from your hands like soap or lotion etc. These things even in minute form can cause problems. I have been putting on gloves now for the past few months..they are cheap enuf, and heck better be safe than sorry... shop around buy a box of 100, alot cheaper than dead corals or fish..or a medical bill. My 2 cents though, Most stuff wont hurt ya..no need to enter your tank with big fears...
b.