they are tropical fish and thrive best at certain ideal water temperature (usually 78-82F).
I don't think anyone keeps their home constantly at 78-82F, it would be too hot for human to feel comfortable, at least I won't.
normally we feel comfortable around 72F, give or take a few deg depends on person to person and that would be a bit cooler for tropical fish, they don't die from that temperature but usually will be less active and grow slower. and air temperature could be different than water temperature.