Went skiing yesterday with the boss and a friend up at A-Basin in Colorado. I put on some sunblock in the morning, then skiied all day... Turns out one application was not enough. I learned afterwards that the intensity of the sun increases by about 6% per 1,000 feet of altitude, so where we were skiing at 13,000 feet, the intensity of the sun was about 78% stronger than at sea level, the UV is less filtered by the atmosphere, plus there were added reflections off the snow, thinner air, etc...

I got baked about as good as the Pop-Tarts.