Evaporator
A solution to create the comfort you always wanted, temperature wise, is the acquisition of an air conditioner. It is an apparatus that works on a refrigerated system and sends conditioned air all around the house. You can choose from portables ones, window units or models that reach the entire house.
If you need to cool a room or two, you should pick the window-mounted air conditioner or the wall-mounted one. Their price range is from $300 to $500.
Now, you might need a central AC if you want you reach the entire house. It is composed out of a central unit (heat pump or forced-air furnace) and ductwork. It is a costly investment, but it will bring you a smaller electric bill and it is quieter than the models presented above.
You can find an economical model such as the one that requires a split central unit, which has the condenser and compressor placed outdoors and the blower or evaporator inside the furnace.
If you already have a heating system, then you can install a separate blower to spread cooled air.