They later called back saying Diego would be there after 1 that very day. Pleasant surprise #2: he arrived with a NEW air conditioner. At least it looked new, and he claimed it was new. He pulled the old one out of the sleeve, warned it would have water in it (but it wet my rugs a bit anyway), and we stuck it on the terrace for the time being. I did a quick clean of the inside of the sleeve with the already dirty towels that had been there to catch the water, and he put the new one in. It was slightly smaller than the space, so he put foam strips along the side. The frame that was to go around the back broke open, so he returned with duct tape to seal the area. Let's hope no bugs or other creatures can get through from outside.
The temperature actually seemed to cool when it was on. One possible problem - it suddenly turned off while he was applying the tape. I'm hoping he knocked out the switch or plug. Otherwise, we could have a fuse or power problem. It's possible the new machine is more than the old outlet can handle. So for the near future, I won't run it when I'm not there to keep tabs.
So of course now that I have a new air conditioner, the weather has been lovely.