A non-airconditioned room must not hinder you to enjoy a plasma viewing experience basta make sure that:
1) If wall mounted, make sure that there is a proper spacing between the wall and the plasma tv since the vents are located at the back (as for my panny plasma)
2) proper ventilation of the room. Electric fan lang ang katapat nyan kaibigan.
3) The Plasma TV must no be put directly to sunlight. kahit LCD nde pede mababad sa araw.
Go for it bro! and enjoy it!