Warmth

Tier 3
Provided by fireplaces or stacking warmth items. The quickest of the warmup amounts.

Tier 2
Provided Lanterns during the day, by most foods, by stoves, and by fireplaces that are a bit far from you.

Tier 1
Provided by Lanterns at night and campfires

Tier -1
The average daytime temperature without any other warmth options. Unlikely to kill you before you can find or make some kind of warmth.

Tier -2
The night time temperature or the temperature of daytime in the final day blizzard. Warm up soon as while you do have some time, this will begin to drain your health quickly.

Tier -3
The temperature of being in water and the nighttime while the final day blizzard is going on. Stack warmth to counter or get out of the water quickly, as this will kill you in seconds.

Preplaced
Tents, caves, the ship and igloos have varying levels of insulation.

Fireplace
Provides the most warmth. Can be found on the ship in the captains quarters, by the beds of the wrecked ship, in the tent of center ice wall Butte, and in the tent at the nitro camp with the workbenches.

When the captain's quarter's fireplace is going, the room itself will give 3rd tier warmth, while the rest of the ship will get 2nd.

Stove
Provides a bit of warmth as well as allows you to cook food. Provides tier 2 warmth around it.

Boiler
While running, the boiler provides tier 2 warmth. If you have no wood and someone is moving the ship it is a good idea. However, a single coal in a wood burner is more efficient then a boiler with no one driving the ship.

Campfire
Can be crafted from the world crafting menu with 3 wood planks and 4 stones. Needs to be fed fuel sources to make it though the night, as its base wood will not last that long. Can be fed anything the boiler can and heat tier is based on how much fuel it has and if you are in a cave or not. Can also cook any raw food dropped near it. Be careful using one while out on your own, as they give off smoke that others can see.

Lantern
The starting item of the Navigator. It can be crafted with 1 scrap and 1 blubber. It can be refueled by dragging a blubber onto it. Provided tier 1 warmth during the day and lowers the night time warmth from Tier -2 to Tier -1 to everyone within its light. It will remain on, using fuel, when dropped. This can be useful if you need to steer the ship at night or during the final day blizzard.

Food
All foods provide a set amount of warmth at a tier 3 rate, though they all have a different amount that they provide. Note that any negative tiers from being outside or the like are not negated as with area of effect warmth. Instead it will start to reduce the warmth you are receiving from food before your current warmth.

Stew
Stew can only be crafted on the ships stove. It can be made from any combination of 12 raw meats, human parts, bone clubs, or blubber. Eating it will provide a set amount of warmth at a tier 3 rate as well as a lot of food. Can be useful to stay alive at night or the final day blizzard if you do not have the time to warm up.

Tea
Tea can be crafted at a stove using 3 dried herbs. Drinking it will provide a set amount of warmth at a tier 3 rate as well as a little bit of food. Can be useful to stay alive at night or the final day blizzard if you do not have the time to warm up.

Cooked Human Meat
Thralls can gain warmth from eating the cooked meat of humans. Like all other foods, it provided a set warmth amount (1/2 the warmth meter) at a tier 3 rate.