Exactly!
Your plants are showing two of the three most common symptoms of heat stress: Upcurled edges from a high temperature:humidity ratio, and actual burn patterns on the leaves where what would have been a mild fertilizer problem has turned into necrotic burned areas. The last symptom would be an overal yellowing of the plants.

Fill out the troubleshooting form, and tell us as much as you can about how your room and exhaust is conficgured, and the lights.
Finally, can you get a close-up of the curled-UNDER leaves in pic #1? There are two or even three things going on there (heat, a possible Mg issue, and the possibility tyhat the plant is either rootbound or N overdosed) and we can figure it out with more information.
You're close to harvest I see so it will mostly be heads up kind of info for next time. Honestly the plnats look like they had been doing very well for a long time.
stinkyattic Reviewed by stinkyattic on . Bright Yellow Patches & leaves Turning Down, & Some plants turning up! - Any Advice? Hi all, this is my first grow, sort of a fumble my way through job! my plants are into their 7th week of flowering now, we only started using nutes since week 4, but only in light amounts the plants are generally healthy but over the last few days one has had problems with the leaves turning down & bright yellow almost dayglow patches on the dark green leaves, any ideas what could be causing this? some of the other plants leaves are turning up, as in the 3rd picture, is this a symptom of Rating: 5