Lebron, how can you say "IME"? You clearly stated you've only had your fish 7 months, so how do you know higher temperatures shorten their lifespan? Because someone told you? Yes, Olympia does know many things, but just because you hear one thing from one person doesn't mean it's true. If someone told you fish also did the backstroke and sang Happy Birthday, would you believe them without doing any further research?
I keep my fish at about 80-82. Never any higher. They come from Thailand, Indonesia, Malaysia, Vietnam, and parts of China. All of these areas can hit 90 degree weather on any given day raising water temperatures in the high 80s. Yes higher temperatures may increase their metabolism, but that's why we feed them the proper amounts. If you notice your fish is getting too thin, you feed them more, correct?
As long as your fish is being kept in the 76-82 degree range he/she will be fine. :)