My dog's appetite is low after heat. What could be the cause?

I'm sorry to hear that Precious isn't feeling well. It is very common that dogs will have a decreased appetite when it gets too hot for them. And this can last for a little while. Our air conditioning did not work for a day last summer and it took a couple of days for my dogs to get back to normal. So, if Precious is otherwise feeling and acting normally, it may just take her a little more time for her appetite to return to normal. Depending on what food you are feeding and how it is preserved, another problem we can have with dry food that is exposed to high temperatures is that the oils can start to go rancid. I would not expect it to be a problem after only a couple of days, but that is also something to be aware of. I will often have owners buy a new bag of the same food to see if their dog will eat that. That will sometimes tell me if the bag of food is starting to spoil. If Precious develops any other signs such as lethargy, vomiting, diarrhea or her appetite continues to decline, I would recommend having your veterinarian examine her.
Good luck! I hope that was helpful and that she feels better soon. Thanks for using Petco Pet Education Center, formerly Petcoach.