No, I mostly use one pair per session - as long as they don't fill up with sweat...

I wipe my hands (with gloves) frequently, wash them occasionally, and generally keep my right hand in the developer, left hand in wash/fix/wash. Any toning is done afterwards, so that's another pair of gloves.

Getting a drop of fixer in the developer isn't the disaster it's made out to be. Unless your fix (or stop) is really horrendously acidic (mine's alkaline) and you use a very dilute unbuffered developer (Pyrocat-HD?), you will not notice any difference before you've put substantial amounts of fixer in the developer.

The first noticable effect of contamination is a drastic increase in grain size, as you get when using monobath processes. The developer will still work until you either have enough fixer in it to actually complete fixing before development gets under way, or the pH has dropped enough for the developer to be inactive.

I'm not encouraging sloppiness, I'm just saying that you don't necessarily have to dump the developer if you think you [i]may[/] have put a hand on tong in it direct from the fixer.