[bkbjones]

Even better than cold, wet towels is cold, wet towels with just a bit of spirits of ammonia. Be sure not to get any in your eyes. However, the night before add just a drop of spirits of ammonia to some water, soak the towels, then put each towel into a Ziploc or other bag that you'll be sure won't leak. Put 'em in the freezer, then pack them in your ice chest the next day.

I'm not certain of the scientific workings of the ammonia, but it does help to cool you down more quickly than just plain ice-cold water, AND the little zip of ammonia triggers something in your system to help you be more alert.

Athletes in many sports have been doing this for years - and more than one umpire, too.

BTW, if you have a small enough rag/cloth, you can do the same thing to these and have them fit very nicely under your cap while you work.