I hear that your plants can't survive temps over 90 degrees. And I'm here to tell you that's not true( depends on the strain) I've grown plants that hit 105 degrees and survived the whole grow. Wasn't the best ,but they survived and the smoke was fire. Lol
yes it is normal for the lower fan leaves to turn yellow and fall off.They have done their job and are being replaced with new growth.Try using a small fan