I would say that since it is going to be so hot, that you would definetly want to hunt early morning and late evening. They will be lounging around most the of mid day because of the heat. Yes they will get thirsty, but you will have to time it right because when they get thirsty since it is so hot. They will only want water and not want to move around much. Let me tell you though, if it is going to be hot during the day, but the last hour of daylight is going to be cool. You better hunt that period.