Not sure this is the best option, but typically I've seen the girls use spray misters filled with really cold ice water and they spray the bottom of their feet. Sure, their feet might get a bit wet, but it beats the burning sensation coming up from the turf through the bottom of the girls' boots. Feet usually dry pretty quickly in that heat so it is only a temporary fix.
Since I appear to be working for Amazon today, here is where I bought ours (you can adjust to a lighter or heavier spray for spraying faces, hair, and jerseys also)
https://www.amazon.com/CoreGear-MIS...coding=UTF8&psc=1&refRID=2P290QGWQ0962A4K33VP
Seems like there should be a better answer tho, would love to hear what others do.