The Crooked River is running plenty cold to be good for the fish too. We are lucky the reservoir levels are so deep, so the source of the river is coming from that chilled reserve!
Still, it is hot in the canyon and mid-day fishing for a person is hot, so take precautions by drinking a lot of water, keeping cool by wading and wearing smart clothing choices to protect you against the heat. Also, you might find from 6 AM to 1 PM and from 6 PM to Dusk to be nicer times to be on the water fishing, and guess what, the hatches will think that too. 
PMD’s, Parachute Adams and Purple Haze, X Caddis, Weiss’s Caddis Missing Link, Larimer’s Yellow Sally and small Hoppers. 
Nymphs- Flashback PT, Scuds, Perdigons, Zebra Midges, Soft Hackle’s, Split Case PMD, 2 Bit PMD and 2 Bit BWO and Rainbow Warriors.