we haven't had rain in over a month and high temps.
Hosta and perennials are burning up. I watered some but way to many
to keep watered.Now are they dying or just going dormant?

Some plants will experience summer dormancy, but without water, some of your plants may be dying. You might try adding a soil conditioner, peat moss, or some other means of water retention to your soil to prevent them from drying out. It has been VERY dry here also, so I have been watering the garden about once a week. How often do you water? What types of plants are you growing? Let us know where you are located, and that may help others give you area specific advice.

Out here in southern Colorado hot & dry is a typical summer! A heavy mulch truly is a money saver and speaking for myself woodchips are where it's at. When I had to protect my Mums, I put down some Revive which is kinda like a granularized manure that is used primarily as a wetting agent for your lawn ( the product retains moisture like those polymer beads, which you could also use ) and after working it in the soil then watering I'd cover them with a thick layer of woodchips. On a personal note I and a few other early arrivers have a kinda bull session before work and I've learned that unflavored gelatin does the same thing. With a thick enough layer you may not have to water at all if you receive a good down pour early in the season. Hope this was helpful.