Science

but I wonder whether some form of dehumidification specifically, rather than just cooling, could also aid survival?

The issue is that in general, dehumidification is energy intensive, just as cooling is. In fact, one of the best ways to dehumidify air is to cool it down. Other non-mechanical solutions, like chemical solutions (e.g., dry hygroscopic material with large surface area) don't have an energy cost during their use, but they have an energy cost in their production and renewal. For example, to dry the hygroscopic material back out to recycle it and re-use it, you must supply a lot of heat energy.

I would be interested in an energy consumption comparison though, between: cooling air to keep it under the red area of the curve; dehumidifying air to keep it under the red area of the curve; and some combination of the two (as most air conditioning units do). It may be the case that dehumidifying is less energy intensive.

but I wonder whether some form of dehumidification specifically, rather than just cooling, could also aid survival?

It's a lot cheaper to just become morlocks and sleep underground during the day and emerge on the surface at night.

Solar/wind power and heat pumps and personal air conditioners are a lot more costly than LED lights to work at night.

Or worse, mass migration north/south out of the hot and humid equatorial regions.