My Mt.Tortoises go through the same thing. They get into the water with only their nostrols above the water line when they have had enough. They also dig a mud wallow and cover their face and legs with mud. You can set up a fan (high powered)in a place it likes to sit or it might figgure it out. I'd go for the mud, but move it around as they become unhealthy. A big pile of "dry leaves works too. Pour the leaves over it at bedding down time for starters. Alot of this depends on the tortoise, I dont know if this affliction occures in their native range. A lot of animales just deal with it or in a tortoises case if its to bad they will just close up inside their shell. Look into Batt houses. Vic