I have had a high-temp situation for quite some time (years ?? ) ... I have never visibly seen any negative effects, but I'm often told, the plants would do better around the suggested 75 degrees fahrenheit ... if it was in my backyard right now, it would be a steady 105 ! ... they tell me Thailand, VietNam, Hawaii, Afghanistan, etc.. all have pretty warm climates ... damned Mother Nature just don't know nuthin' 'bout no growin' ... after my present plants finish, I am going to build a new ceiling for my cabinet, and re-do my ventilation setup, should get me down where I belong ... problem is, I am presently venting back into my adjoining room ... the new setup will vent it directly outside, for my neighbors to enjoy :S3:... but, honestly, I'm not doing it for the plants, I'm doing it for ME, tired of heating my house with a 400-watt sodium :smokin: