Check out my log I live in South west florida, temps where I am are 85-100 everyday. Todays heat index was 115,but thats just me bitching lol. My plants seem to be growing just fine with the heat, they were in a grwbox outside with 3, 90CFM pc fans ( 1 intake, 2 exhuast ) and the heat deff did NOT stop them from growing. Photosynthesis continued on at what I would think to be fulll force considering they were LST'ed all to hell, and still had to be taken out of the growbox, because they grew so high that they were about 2 and a half inches from my 400W HPS. Turned them almost a see through yellow. But didnt stunt growth...maybe just tough ass plants but they are doing loverly, except for not flowering on schedule due to light leaks! Good luck mang! Oh yea, if you add CO2 to your set up, photosythesis will be more effective with the higher temps then w/o CO2.