It might be hot up there on the roof, but with the typical black shingles you seem to get a great tan!
That's funny this thread came up when it did, I have recently gone back to roofing and finish carpentry and was up on a roof for the first time in eight years three weeks ago. As with any trade you get used to the heat, the physical demands, the heights and the awkward ladders and staging. Try carrying 120 lb rolls of tar paper up a 30 foot fiberglass ladder, then you really respect the what the contractors do! Good luck with your roof FLL, you can learn a lot doing it yourself!