I’m no expert. Stop reading here if that’s not good enough.

My understanding is that in cathode ray screens, the old-style non-flat types, heat would make a difference. In LCD and LED screens, so little heat is produced by showing images, it is probably negligible. One of them, I forgot which type, does black by just turning the light off in that spot. So the type of screen used probably matters here.

You can see massive ad screens even in hot places. Now, there may be insulation in use and/or A/C. My guess would be if they can operate a huge ass screen in 100F 40C weather to get me to buy shit, the combined energy costs cannot be exorbitant. And my guess is further that’s mostly to prevent the hardware from melting in the sun, whether the screen is on or off.