I’m sure that the ACE guys can give better detail, but a few options come to mind:
- a class-specific outfit that has a small buff to warm the miner up (could be a periodic thing so that the miner doesn’t get outright immunity to cold but can, like, warm themself up intermittently on a long cool-down), could come with a trade-off e.g. one set of miner clothes improves speed or carrying capacity while the winter version offers strong protection from cold but at a small speed penalty
- a class skill for the same general premise, only this would allow the miner to warm themself up “as needed” so it’s much more powerful (there can still be a cool-down to make them unable to infinitely sustain warmth, of course.) You’d probably want to have a down-side, e.g. the “casting animation” for the buff might last a significant time as the miner “sits down and warms themself at a small lamp/fire/etc.” (purely cosmetic animation, but it’s a good excuse to have the miner take a small pause – they can mine or they can warm up but not both at the same time.)
- a flavourful and interesting alternative would be to give the miner the ability to make a small temporary campfire/brazier out of coal that they find. This way it’s not “free” warmth but it’s not prohibitively expensive, and they can use it to benefit other hearthlings too! It would have to be tied to the coal items themselves (i.e. select a particular piece of coal to ignite, it gets transformed into this “mining campfire” item) so you don’t have to worry about giving the miner a crafting queue – just like how the trapper is able to use a few items placed in the world without requiring having a crafting queue of its own. It’s basically a “oh yikes someone’s cold, quickly burn the nearest thing to warm them up!” option, but giving the player enough control to make sure it… actually works well (i.e. you can pause mining and have the miner do it immediately, on-site, for immediate benefits) rather than just allocating the task and hoping it fires off in time to be useful hahaha! The item would be temporary, but you could potentially have the option to re-fuel it with firewood (meaning you save on coal – set up the campfire and as long as you keep it fuelled you can use nice cheap firewood to keep it burning all winter!) It’s more complicated than a simple buff or just building a regular brazier in the mining site, but adds a nice little story and gives the miner a unique winter utility.