I can appreciate your concern, Jim and I know you have been fishing the Bow for almost 50 years and have the expertise and experience to mitigate your fishing impacts, so my post is meant as general info for the wider fishing community. It's difficult to predict what conditions will be through August, but they certainly won't improve until we get cooler temps as flow rates are sure to decline without some rain.
I fished a few times this week and mid day water temp averaged 67 F. I caught a nice healthy Rainbow today, in the city, around 1:00, that put up a good fight and recovered quickly. Thermally stressed fish will retreat to deeper, cooler water with less direct UV exposure and generally won't sit in 16" of slow water, a foot off the bank, eating my #20 Trico. The Bow still has good flow (currently at 110 cms) and the Bearspaw dam is a bottom draw which releases cooler water into the river, averaging 6-7 C, year round and that has certainly helped with keeping water temps down. I Floated Mac too Janssen's yesterday and water temps were 64 F at about 10:00 am. We started early, around 6:30 am. It gets hot every summer in late July/August and this year is no different. Just check water temps through the day where you are fishing. Start early and call it a day if it hits 69-70 F, or sooner if the trout are sluggish and don't recover quickly, which is a sure sign of thermal stress/low dissolved oxygen. And anglers need to cut out the 5 minute grip n grin photo shoot's for their instagram/facebook page. Land them quickly and release them immediately. Keep em' wet!