This is just a simple idea that I think would make the game better:
A type of metal canister that can keep liquids hot for longer than in other containers.
To craft, perhaps just extra metal, or plastic around a metal container?
It seems a little silly to me to store hot coffee and tea in a little plastic bottle, and the heat retention would be a bonus.
If it’s just a simple mug, two units of water/coffee/tea would be reasonable, with just a heavier weight than the plastic bottle, but if it’s a larger thermos, it could hold 6-10 units, like a canteen.
In a quality thermos/mug, a hot liquid can stay hot for almost a whole day.
So it’s really not a big thing, just a small bit of content that I think would be a meaningful addition to the game.