Help, my bonsai Ficus overheated and wilted.?

I have a thirty year old ficus Bonsai that I decided to take to the local nursery, to see if it needed to be repotted. After finding out that it was in perfect condition and did not need to be repotted I left happy. The shop keeper told me that it liked heat, so I thought not much of leaving it in my car for a few minutes when I went shopping. Bad mistake. Now all of the leaves are shriveled up and the tree looks miserable. I'm so sad. Any tips on what I should do to get it going again? Other than putting it back in the environment where it was living happily? Should I prune it? Thanks for any help!