Cant keep grow room temps down,plants ok ?

Say guys/gals I have a problem with afternoon temps on nice days in my grow room In a second story room in my shop. It's well insulated all around but still with 3 vented 600 watts and 1 - 250 non vented ,with a 8" carbon filter sucking air out at ceiling height and door open with screen door on now to help vent, 4 obsoleting fans move thing around well enough but I am hitting mid 80's + sometimes then cools back down around 7 pm midd 70's until about noon next day. So about 6-7 hrs of high temps. Plants are 4 weeks into budding 5'&6' tall. they look ok but I lolleypoped then up about a foot cause some of the lower limbs were never going to mature plus dying off fan leave on lower level as well. How bad is this going to effect my over all yield with this stress to my plants ? Any you experienced growers have a clue ? and yes I will do some changes to get more outside air exchange next grow but don't want to do work in the room now if I don't have to .... irst grow noob

get another extractor to help dump some more hot air out if u can mate are u hydro or soil if hydro watch your res temps aswell

It got worse and hit 90 F so I added a 6 inch intake vent in the room with a 400 cfm fan pulling air in from out side and a 6" exit fan on the other side of room extracting , plus the 750 cfm carbon already extracting out at ceiling level got me to a steady 79-80 on hot days. Just posed some pic's on the 600 club thread didn't turn out to bad considering.

Yeah that was prolly the best thing you could have done, some hot days lately here in the PNW!

I'm lucky where I live, it might get in the nineties 3-4 times a year when it does I put ice in my res to absorb the excess heat in the tents.