I don't know why I'm so confused lol. But okay so I was just thinking one thermometer/hygrometer (the one you linked) so that would be used for the cool side, but the only other thing would be the probe for the thermostat on the outside of the glass under the UTH so that's why I was saying nothing to measure the remaining side. I'd need to buy two of those thermometer/hygrometers that you linked correct? Unless one only needs temp and the other both temp and humidity? I feel like that's a lot of wires going around too.
Otherwise of course just use the IR temp gun for the remaining side but that won't measure humidity....
And about the UTH thank you very much for that tip because yeah it's one of those adhesive ones so I'll try to be very careful!