I was there, doing my first full, and it was BRUTAL! I started in front of F, roughly middle of the pack, and took it easy from the start, running about a minute slower than Marathon pace. It was sticky but okay, but the sun came up just about the time I hit MK (mile 10ish) and BAKED us. After AK, during the road and parking lot miles, it was scary hot with no shade and the asphalt just keeping in the heat, and people were dropping all over the place.
I ended up walking the entire second half as my heart rate would spike even trying intervals. I was about 30 minutes ahead of the balloons when the red flag was called and the course shortened, so just missed Blizzard Beach. Disappointed but honestly, I understand why. They said the heat index at 11am hit 90! It was like early summer weather.