chicken saddles.... question

I wanted to add a quick question about these.. (i've renamed them dresses)
I had to take them off our hens that had them on because I needed to wash them (bought mine from lovemychix BTW-they wash and stay in tact wonderfully! I didn't have any doubt but wanted everyone to know)
It was quite hot here for about 3-5 days and I didn't put them back on the girls because I didn't want them to be too hot.....
My question(s) is..... Are they going to have to wear these forever? Will the feathers ever grow back under the 'dress'?
are they fine to wear them all summer even if it gets to be very hot?
I'm going to have to put them back on them because some of the girls are featherless and red now. .... I do have to get a few more.... but I have @ least 2 girls that have no feather loss at all. Must be he's not interested in them? (ok, so perhaps no one can really answer that last question)

Thanks for any answers!