Higher elevation (or cooler climate) cities/towns NEAR the Big Cities

I want to explore Brazil as a possible place to do an early retirement on a pension.  I know I will like the people (have met Brazilians here in Calif.) but I don't like hot humid tropical climates in general--so I need to know if there is a spot near Rio or Sao Paulo or Brasilia that has a significantly cooler climate than the Big City itself. (I want to be near a Big City).  I came across something on the web stating there are mountains near Rio...true? ... Thanks for any TIPS!

Rio and Brasilia are extremely hot, even durting winter.
São Paulo has a cooler weather, especialy between april and august.

If you are looking for pleasant places near big cities with good wheather, check the states in the South. Paraná, Santa Catarina and Rio Grande do Sul.
Curitiba is a lovely city with an average temperature of 25 celsius during the day.