If they are only an inch long, or less, it could be that they have not been pollinated. The hot weather may have something to do with that. I have learned that the female flower sometimes produces a tiny squash, but if it is not properly pollinated, it just dies off. My zucchini aren't producing either. I don't think I have any female flowers.
I miss read your post. Try adding some powdered limestone to the soil and water it in. That should cure the dying squash.If there are a ton of small squash on one plant. remove a few. Make sure it's not too wet.