I wonder if I will be able to keep running outside when summer heats up. In the past, I haven't been able to tolerate anything over 70! I love running at 50 degrees or so. I was able to build up my tolerance to riding in 80+ degree temperatures, so I guess I can do it with running. When I first started riding, I would go to spin on any day it was hot and humid. Now, I would at least go out early in the AM, for a short ride, but after riding in southern Spain in May, I can just about do anything.