It'll affect amount of bud, that's for sure. However, it can be done at high temps. I'm indoor now, but last year I had some outdoor AK47 that turned out really nice. Went through the entire Arizona summer....I'm talking 115 degrees at times. I had some tomato cloth partially covering it at times, providing diffused indirect sunlight. Through it all, it looked pretty healthy. There was definately a period of weeks where the plants didn't seem to do much - just hanging on...very little growth. One note... they grow shitloads in north-central Mexico and it's often in the mid 90's. It may have more to do with the tolerance of the strain than people realize.