Hi,
Sweat rash or milaria is a skin disease marked by small and itchy rashes. This is a common ailment in hot and humid conditions, such as in the tropics and during the summer season. This occurs when the sweat gland ducts get plugged due to dead skin cells or bacteria. The trapped sweat then leads to irritation, itching and to a rash of very small blisters. This usually occurs in the face, neck, under the breasts and under the scrotum and areas of the body that may rub against clothing, such as the back, chest, and stomach. This can be prevented by avoiding activities that induce sweating, using air conditioning to cool the environment, or wearing light clothing. However, with the nature of your work, it would be a challenge to do so. You can also try showering frequently because this may also help. Take care and keep us posted.
Let me also add this...
I am a 34 yr old male that is 5'10" 190 lbs. I am a NON smoker. I am a baseball coach so I am outside ALL the time