In the summer, we hunt at night and bring water for the dogs and we know where all of the water is on the property so we can let the dogs keep cool during the hunt. We let them cool down real good in between runs and if they get on an unexpected long run, we make sure to bring water to them to drink and we wet them down some. Its better to keep them from overheating than to try to treat them after they overheat. I also wet the dogs down with a water hose before we ever leave the house on hot summer nights. And we let them wind from the wheeler when its really hot to save their legs.
pretty good good advice.. just keep water handy dip them in a tank, or creek before or during the hunt, switch out dogs often if you have more than one pack to run, keep them watered, and if it gets to hot just load up and come back another day it aint worth heat stroking a dog...