The heat will definitely take a toll on them so I would wait until it is cooled off some. But keep in mind that a lot of times the prolifs will look like death warmed over after planting because they are trying to get established and the foliage will turn yellow and sometimes it will look like they died and then all of a sudden the green starts to reappear.
If you plan to plant them back next to the mama plant then you can go ahead and do it and use the mama's foliage to cover the prolif to protect it from the heat/sun. I do this sometimes and I also pot mine up and put in the shade until good and established. But I don't see a problem with leaving them in the jars for a week or two as long as you are changing the water
