When Is Hot Too Hot?

High humidity ACTUALLY helps cooling because it increases the heat exchange of any air heat exchanger

Stock gauges are notoriously "uncalibrated." Until you really know what the temp is, you are just guessing

Stainless steel spring? Thrash around the hardware stores for some steel wire, or maybe some welding filler rod?? and wind your own. All you need is something like a broom or shovel handle