Underground living in the tropics

I've been searching and searching online but can't find any info on how cool it gets going underground in the tropics.  This is where the temperature above ground rarely gets below 65F even in the winter at night.  I thought of buying a shipping container or 2 and planting them on top of each other and using the lower one for cooling, refridgeration, etc, while the top one would poke out of the ground by about 2' for light and ventilation.  Windows would be mounted at the top of the walls of course so they meet the ceiling.  Horizontal sliders I guess.  Or I might go with lots of small windows so window bars won't be needed.  Once that window gets small enough no one can get in. 

So is there any advantage of underground living where the temperature never gets cool?
I could have looked up mine temperatures but that's going to be way lower than I can dig.