Thank you for your question, Dolores.  There are several reasons tomatoes do not produce fruit, and you have identified the most obvious one.  If temperatures exceed 85 degrees, the plants cease producing blooms and/or the pollen becomes so sticky from the heat that pollination does not occur.  Here is an Extension article that explains this phenomenon:  https://hgic.clemson.edu/why-did-my-tomatoes-stop-producing-fruit/    Fertilization can, along with hydration, also impact the plant's productivity.  There is more information here:  https://catalog.extension.oregonstate.edu/ec1333/html

Good luck!