Whales, do you plan on expanding the current "overheating" system, maybe at least providing us with some more indicators? I've never got any idea how hot I am until its too late (maybe I'm missing something).
Will we eventually have to deal with frosts and cold spells and frostbite (a la Unreal World)?
Extreme heat waves (though it seems like thats always the state we're in now considering how little clothes are needed to quickly get overheated)?
If not, maybe extremely hot/cold area? (sections of science labs, maybe? Cryo rooms... even freezers in a butchers or restaurant. Nice strong doors, keeps out all the zombies, but super cold inside?)
This could easily tie into firefighter gear - it will protect you from overheating when near fire for a while (note that normal firefighter gear is NOT fireproof, merely fire retardant. It will not burn, but will not protect you from actually standing in fire. It does work really well against ambient heat and steam, though. You could give it actual fire protection, but make it degrade quickly?). You'd need a proximity suit for actual flame resistance (which would probably require a science lab or military base), and even that would degrade steadily while standing in flame, if not as fast as a normal fire suit, giving only temporary immunity. (This is the kind of thing lava researchers wear)
If nothing else, you could have a constant "temperature" based on some starting region - Do you start in the tropics? The temperate regions? Somewhere subarctic, like Canada?
Of course, that would eventually be a lot of work, since right now fire doesn't even generate light, forget heat. It seems to act more like... acid, I guess? Burns on contact, but no issues from proximity.
And finally:
Yes, please give us the option to put things on spaces next to us, or maybe even throw liquids without throwing the container! (Scoop up the zombie acid and use it as a weapon, mwahahah!)