3/20 had temps of 92F on rim (110F on canyon floor) and trails were closed 11am-5pm. Projections for 3/21 were high of 95F on rim and projected trail closures again 11am-5pm so ranger suggested starting any trail activity in the dark, which is what I did. It was scary, I'm gonna be honest (burrow owl on the trail had me yipping like a coyote) but saved me from the heat. Ran alone with 4, 16 oz flasks in vest and 1, 16oz hand held of water and electrolytes along with my chews and wore a headlamp and had one small handheld light (or a rock after I saw a pair of eyes glowing the dark). Reached the top of Rock Garden as the sun was coming up and headed back in tolerable 60s temps. Reached the finish as it started to warm up. Trails were in great condition and there are signs every .1 miles which makes it an easy route to follow even if you aren't familiar. Thanks for sharing this route!