First coco grow, suspected heat stress

[ajc1213]

Hey all, temps have been up to 30 cel in my space, some leaves have strange edges, some are super short, some are slightly yellow, some are curling. Just wanted to confirm if this is all heat stress or if it looks like another issue too.
I'm already doing what I can to cut the heat ( lights off during days hot period, venting what I can, fans, lower power on lights) but I'm still struggling to get it below 28 cel. I can't really open the door or window due to stealth issues.
As I said, just trying to confirm if this is just heat causing the problems or does it look like something else that I need to deal with? I don't want an extra problem compounding the heat. Thanks in advance!

 

[ajc1213]

No clue what's happened to this one, seems stuck compared to the rest. They're nearly 3 weeks in now. Auto watermelon from royal queen

 

[Galgrows]

So they all autos? What are your lights running at time wise? What's the plan when they flower? It's gonna smell up the building, clothes.

 

[Thukah]

I think 86 F is fine as long as you have airflow, I would lean more towards over watering or poor drainage.