I hear ya.
I always shot in cotton tees but in locations in the country like Nationals, Claythorne Lodge, Minnesota Horse and Hunt Club, etc. they don't work too well. Humidity being the main culprit.
I went to synthetic "wicking" under armour type fabrics. It's about the best you can do.
Drape one of those blue Cool Towels ya wet in an ice chest or water cooler around your neck. They will help.
