When it's real hot, one thing I would make sure to do is get out while it's still dark. My experience in Nevada in August has been that I've seen some of the best bucks watering very early, and then heading for shade soon after. Last year, my son and I were on an 85" buck that another hunter killed, and they saw it in their headlights when driving out, and it was already returning from drinking. If those guys didn't see it in their headlights, my son would have killed it, but simple luck made them aware of it. Some of the best bucks I've seen in California and Nevada have been very early and late drinkers, and spend their days in thick cover, not what most hunters would expect.