I take my nephew's Golden for a 4 mile walk 3 times a week. It's been 90 degrees here just about every day and I wonder if I should cut back on the distance. 90% of our walk is in the shade and I give him 2 rest breaks. I carry a military style canteen and fill it from the fountains and pour the water into the canteen holder(mess kit) for him so he gets plenty of water. He's tired when we get back, but not exhausted. What do you think? BTW, we walk around 2-3 PM which is not the ideal time, but the only time I have.