I've read about nesting failures in Oregon from the heat so naturally, I was worried about all the nest boxes I have. Below are the results from my boxes, the best I can tell:
Tree Swallows - one box is a second attempt, the first one I thought had young being fed but I don't know the final outcome; now the female is sitting on eggs. Another box had 4 dead young that appeared to be close to fledging (I suspect the heat got them). After opening the box this morning, I didn't have the stomach to open anymore for fear of bad news.
Violet-green Swallows - mom is sitting on eggs after a late start due to WB Nuthatches successfully using the box before the VGSW claimed it.
Barn Owls - 3 out of 4 that were banded are still in the box and should fledge any day now. I'm guessing the 4th jumped out too early, well before time to fledge.
When I first read of the heat problems I had to do something so I stapled disposable puppy pads (that our puppy no longer needs), white side out to the sunny side of the boxes... hopefully, some help. It's always tough for the birds, but this earlier heatwave makes it a bit tougher on them.