@Rumble, I totally agree. I used to like playing on a mud (that has now since died) that had some features I really liked: item durability and learning points. Sure, you could have the heavy suit of full plate mail... but after a tough fight you ended up spending a LOT to get it repaired. The learning points system on there was somewhat broken, but replaced practices: the higher your mental stats, the more LP you learned and less was spent when raising skills. However, when it came to finding adventure/something to do on there, it was pretty bad. Lots of empty rooms, as they tried making a grid that you would travel on. I'm not really against this, unless they don't add much content or stuff to find (which was the case on there). I've become a fan, over time, of throwing situations at players that don't require mindless fighting; to be fair, in the case of the Frostfall Mountains, just about every NPC in the starting village will warn them about how cold it is and wearing metal armor is a terrible idea.
Actually, that's similar to what I had in mind, Whiskey! Adding another stat, and it starts at 0; depending on whether a player is in a hot room (desert, humid swamp perhaps) or a cold one (arctic, Frostfall Mountains), the value goes up and down.
For the mountains, as an example, let's say the base value that Temperature drops by is 20. From there, each piece of leather would decrease that by 1 while hide and fur would decrease it by 2 (wearing 5 pieces of fur armor would cut it down to 10, for example). Each piece of metal gear would increase that rate of Temperature drop by 2. Once it hits 100, damage is applied: GET_HIT(ch) = Temperature - 100; That might not seem like much, but given that characters start around with around 11-20hp with no endurance bonuses...
That would mean you'd have 5 ticks to get through the mountains before taking damage (and likely dying). That seems a bit too easy, except in combination with encumbrance. Mountains already eat up a lot of movement points (default is something like 3-5? I can't remember offhand), but if the character is encumbered by lots of armor or other goods, it's going to take him longer to get through those mountains (and having to rest to get movement back is going to be fatal).
I might make the point in which a player takes damage depend on the endurance stat: for every 1 point in endurance, the character can handle +-10 points in the Temperature stat. It severely punishes those with low endurance, but then again I can't think of many players that would treat it like a dump stat.
On the matter of recovery: rate would be 5, plus 1 for each piece of leather and 2 for each piece of hide/fur. In the case of that area I'm working on, I will need to leave a cave or two to allow players to rest and warm up.
Come to think of it... I'm going to have to find out how to not get typical weather messages while in these mountains. "It starts to rain." "Uhhhh it's raining AND snowing?!?!"
Anyways, I appreciate the feedback and the interest. I look forward to moving past the brainstorming stage and coding it all in.