Red/ brown burnt looking leaf edges

Like DissNoof said, this look like a magnesium deficiency and a heat problem. Make sure your lamps are at the right distance, get them some fresh/cold air to cooldown a bit. And what growninggrannie said, we don't have much info to give you the best advice.

hey there UKG, that's magnesium deficiency , plants need more Mg to regulate metabolism when it's hotter . you'd do well to add some calmag next watering and get the temperature under control. Hope this helps ! 🚀

I can't figure out which diary this relates to... (if you start your question from your diary - down at the bottom - it helps us help you)... Not knowing, therefore, anything about this grow except that it got hot in your tent, I would say it honestly looks like you've got an overabundance of nitrogen going on there - and the heat didn't help much. I would check the PH of your runoff to make sure it's in range... if you're giving the same amount of grow nutes you did during the veg period, knock back on them as the flowering stage doesn't need as much. Good luck!