I cut my cane begonias and stick them in the pot to make a bushy plant vs a tall plant. I am pretty good at keeping the canes alive I kill any other kind of begonia.

They root easy in water or moist soil. Most of the time in the summer I just cut a cane and stick in in the pot with momma.

Hey Carol, I looked like that yesterday myself because the weather set my inner ear into a spin.

Wish I had an answer for you but I was just looking at my Tea Rose babies in the greenhouse and the Cane babies and I have them sitting in water to keep them from dying in the heat. They are looking great and I think they like all that water at this time.

Have a great day. I am going to try and buy a new HEAD on eBay. Mine needs replacing.

....you guys going thru that heat...wow. It's really bad. Here we have unusually rainy summer....actually we haven't had summer yet

The more leaf area exposed on plants, the more moisture loss thru the leaves if you aren't getting rains (which the big leaves love as they absorb all that moisture). I would cut them back...but not cut them down. Leave some mature leaves. Maybe it will cut into the cycle of "oh, lots of water so now I will bloom" and the plant will retain it's energy. Just a thought....