First off, relax. They look ok. The "damage" does not look like heat stress/bleaching for two reasons. First, bleaching (light too intense) causes the leaves to show pale splotches, or even yellowed splotches of it is really bad. And bleaching would show on all exposed leaves of the plant. Second reason is that heat stress causes the plants to wither and become limp, as water in the plant evaporates faster than it is absorbed. This would show on all the leaves and stems. However, you topmost growth (new growth) appears to strong, dense, and a healthy shade of green. It is possible that the discolored, curled leaves are the result of fertilizer burn, but none of your new growth has yellowed tips, so this is unlikely. Instead, what is most likely is that your plant is shuttling most of its nutrients and energy to sustain rapid new growth. Within a matter of days, those browned leaves will be obsolete. Just in case, give them a heavy watering of pure water next time they need it, and keep an eye on new and middle growth for signs of over-fert. In all, you dank looks....well, dank! You're doing all right. I wish you many stinky buds!
