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.
Yeah there are a lot of trees that grow up to 4ft a year (maples, firs). Buy a 10ft tree, water and fertilize it as needed, and you can shade your house in a few years.