Umm, hot for me (and I would argue for most of us in CO) is anything over 95, but this is as reported by news stations. Since heat emanating off of road surfaces can be much higher. I guess on my particular ride that I mentioned the ride data from my Garmin only reported around 91 degrees during that particular climb, but it feel particularly warm due to the fresh black pavement (the difference felt noticeable when I got off the new pavement to older pavement that had faded). An article posted by "rdubbz" did mention rider size/weight as being a contributing factor. The hill was pretty steep, at least steeper than what I typically see because I don't usually enjoy climbing, but that's a different subject altogether. I'm 230lbs and was having a hard time keeping my speed at a comfortable spot. I didn't want to push it. (the mentioned article did advise that one could still blow a tube due to heat building up.)