Watch your dog and look for behavior changes which could be minor when they start to heat stress. Had my dog in the hayfield behind the house when it all was new to me and didn't pick up on the change soon enough. Came on fast, by the time we got back to the house I had to wet him down. I'd take a couple gallon jugs of cold water with me to be safe, 1/4 to 1/3 water, freeze, fill before leaving. If they get to nonstop panting and excessive drooling wet down immediately.
Some years ago it was in the low 80's for the pheasant opener and tragically too many good dogs were lost because the owners let them run too long and weren't prepared to cool them down immediately.
