I'm relatively new as well but roots generally have an optimal temperature of around 67 degrees F. It can probably handle slightly higher temps but not sure when disease kicks in. One thing you could do is to cool just the roots with a circulating water cooler, plants can handle much warmer air temperatures than are ideal as long as their roots are kept cool. Water coolers generally cost a bit new but there are some DIY versions that can cost under $100 (I'm thinking of doing the same).