Probably nothing new to anyone here, but I thought I'd add to this. Creating heat is much easier to do then to move it around. The mechanics of cooling is to take the heat from somewhere it isn't wanted, and putting it where it's unobjectionable. You'd likely want to dump the heat outside the dome or whatever you're using to conceal your kerbals from the atmosphere. Moving heat out into 149 degree temperatures would need a special condensing unit capable of handling high pressure. I'm not sure the kind of refrigerants kerbals have, but using IRL examples, they'd probably use R-114. The boiling point is around 3.5 degrees, allowing the temperature to be brought down to a comfortable 20-30 degrees. The units would need to be able to handle extremely high pressures within the condensing coil, as the pressure would have to be roughly 455 PSI (A bit higher, as 455 PSI brings the boiling point to 150 degrees, and we would want it to be more around the range of 170 dgrees). All this equipment is going to be difficult to maintain, not to mention expensive. Lots of work involved. The alternative, Duna, is colder, but as I said earlier creating heat is much simpler. Find something to burn, burn it, and blow a fan past a heat exchanger. DONE. Equipment is much easier to maintain and keep in working order. I would love to set up a base on Eve (It's such a beautiful planet), but if squad makes colonizing realistic, with temperatures, pressures, radiation, etc. affecting kerbals, then Duna seems like the better option to me.