My experience with doing outdoor activities in areas with lots of pit vipers (Georgia, Florida and Tennessee) was that they weren't too active when it was really hot. The times that I did see copperheads that were out and active, it was late spring or early fall and temps were in the 80s. The also stayed out of direct sunlight, so 95 sounds really hot. I'd think that 70 at night and 85 during the day would be a much more natural environment for one.
The one time that I did see a lot of them out and sunning, it was only 65 degrees out, but it was under extenuating circumstances - their normal dens were flooded out by a river after a hurricane went inland. New River Gorge in WV seems to have a lot of them around.