your heat stress is probaly caused by radient heat. not the heat of the room. my room is up to 95 F with no signs of heat stress. but back when the lamps got too close a few times we had some heat stress.

so just back off the lamps.

what are the effects of heat stress, you getting deformed leafs? at the top
harris7 Reviewed by harris7 on . Impact of heat stress during veg? Hi, I have some young ones, about 3 weeks old, under a 400watt mh lamp, they are about two feet below it, with a six inch personal fan blowing over the canopy. They are showing signs of heat stress as some plants have only developing 3 or 4 blades per leaf. Other than that though the plants seem very healthy with bushy, vigorous growth. Is this going to create signifigant problems? The flowering room has much better temerature control and will stay in the appropriate range (below 80) Rating: 5