Keep it well watered and provide shade for it during the hottest parts of the day (you can place a lawn chair over it) etc...
Please no fertilizer for now... Hopefully it will releaf and be fine for you...

What Jim said. Its been gawdawful hot in Virginia and will continue to be hot this week. That's a small plant, I'd put a chicken wire cage around it to protect it from rabbits, rambunctious dogs and soccer balls. Good luck!

Remember this; As long as the canes are green, it's not dead. Most David Austin roses slow down to a crawl when it is extremely hot. Somehow give it shade from noon on. Keep it moist but not soaked. Don't feed it until next spring. Right now it just wants to grow a good root system. 1st year sleep, 2nd year creep, 3rd year leap. You'll see a difference next year and the 3rd year it should go crazy.

Glad you mentioned about those pesky rabbits cecily as I forgot...lol
I always cage our young plants now..