I am assuming it's an enclosed glass GH? Well, heat will rise. Your hottest are will be the roof, so if you could ever vent that then it wold help tremendously. Second, 92 is not a bad temp. It can get even warmer and for cooler growing plants just remember to keep them wet during that time. A misting system will definitely help keep the air damp and the plants moist during the heat.
Just remember that with the heat the plants need that cooler temp at night. Especially the cooler growing ones.