True, it was 98F out there. Mostly in the shade, but 98F in the shade is still 98F. That just makes it unpleasant, and I can work through unpleasantness.
The reason I paid attention to was my body saying "Don't do this." I have a great deal of history of ignoring what my body is saying to me, and paying attention to it is a good thing and something I need to learn to be much better at. But I do like knowing *why* it is telling me to do, or not to, something. Bodies aren't always very good at communication, and mine in particular doesn't spend a lot of time or effort explaining itself.
So heat was probably not the reason. I got the last load out of the storage area this morning, so my body was fine with doing physical work, and it was less than a half-load, so exhaustion wasn't the reason either. Adequate reason to take a nap, which I did. So why didn't I get up from my nap and go sort boxes? Or, more accurately, why did I consider my idea, and then listen to my body's veto of it?
Still working on this. Right now, I don't know.
Friend Steve will be by tonight, and will take half a dozen bookcases, and whatever else looks good. I hope to persuade him to take the electric cooler -- it's a standard picnic chest with a built-in cooling unit, so if you have a place to plug it in it becomes an actual refrigerator. In the morning I'll call Goodwill, and they can take the entertainment center, the kitchen chairs, the card tables and chairs, and probably some other stuff. And then I can see what's left and make some decisions about it.