Heat problems, but half of the day only.

My lights are ON at NIGHT and I get low 80s temps in the cab.
Lights are OFF during the DAY, but because of the outside temps during the day, my cab is in the low 90s.

Should I be concerned about heat stress if it's only half the time? I have feminized plants and I'm really worried about getting hermies.

ya that can cause some stress, plants like there nights cooler than there days. try relocating your cab to a spot that is less succeptable to temp change. you could add insulation to your cab to keep the heat out. 90 degree temps will stress your plant