Will they survive?

Under this sheet are 2 hydrangea plants. I planted them 4 weeks ago and mostly they have survived our clay soil and windswept environment. But when we had a day of very hot winds, the leaves began to curl up and i started worrying about whether all my efforts with a pickaxe to make a hole big enough for each of them might have been wasted.
Some ladies at church said to place sheets over the bushes on hot days, so in prep for a 33C sunny day, that's what I have done.
Fingers crossed!