Temperature & Furnace Guide
Temperature Is the Game
In Season 2, temperature is not a side mechanic. It is the mechanic. Every decision you make — what to build, where to teleport, which alliance events to prioritize — connects back to keeping your base warm. If you treat temperature as optional, you will spend half the season locked out of combat.
If your base temperature drops below -20C, you cannot start rallies or teleport. Resource production slows to a crawl, healing speed drops, and troop morale tanks your combat effectiveness. This is not a minor debuff — it is a full lockout. Everything in this guide exists to prevent that from happening to you.
What Happens at Each Temperature Range
Temperature affects your base on a sliding scale. The colder you get, the worse things become:
The goal is not just to survive at -19C. The goal is to stay as warm as possible, ideally at 0C or above. Warmer bases produce faster, heal faster, and fight better. Alliances that maintain high temperatures compound their advantage every single day.
The High-Heat Furnace
Your High-Heat Furnace is the single most important building in Season 2. It raises your base temperature and increases virus resistance. Max level is 30.
Key Facts
- Independent of HQ level — your furnace levels up on its own track, separate from your headquarters
- Requires Titanium Alloy — the primary upgrade material, produced by Titanium Alloy Factories
- Requires Coal to operate — the furnace burns coal continuously. If you run out, your temperature drops
- Each level provides both temperature AND virus resistance — this is a double benefit that makes furnace upgrades the highest-value activity in Season 2
Furnace Upgrade Priority
Your furnace is your number one upgrade priority in Season 2. Period. It provides temperature (survival) and virus resistance (combat power) simultaneously. No other building or research gives you this much value per upgrade. If you have to choose between upgrading your furnace and anything else, choose the furnace.
Furnace Level Milestones
The furnace unlocks additional functionality as you level it:
Titanium Alloy Factories
Titanium Alloy is the bottleneck resource for furnace upgrades. You produce it in Titanium Alloy Factories.
How Many Can You Build?
- Base game: Up to 4 Titanium Alloy Factories
- Season Pass: Unlocks a 5th factory
- Each factory can be upgraded to increase production speed
Factory Strategy
- Build all 4 factories as early as possible — do not wait
- Upgrade them aggressively — higher-level factories produce titanium faster, and every hour of faster production means earlier furnace upgrades
- If you have the season pass, build and upgrade the 5th factory immediately — the titanium advantage compounds over the entire season
- Never let factories sit idle. If production is complete, start the next batch. Titanium Alloy is always needed
The difference between 4 factories and 5 factories over a full season is enormous. A 5th factory gives you 25% more titanium production. Over 60+ days, that is multiple extra furnace levels. If you are considering the season pass, the 5th factory alone is one of the strongest reasons to buy it.
The Alliance Furnace
The Alliance Furnace is a shared heat source placed by your alliance leadership. It heats a wide area around it, providing a temperature bonus to all alliance members whose bases are nearby.
Why It Matters
- Provides a significant heat bonus that stacks with your personal furnace
- Covers a wide radius — your entire alliance hive should be within range
- During Cold Wave events, the alliance furnace can be the difference between staying above -20C and getting locked out
- Losing the alliance furnace during Beast Crisis removes this heat source for everyone nearby
Alliance Furnace Strategy
- Stay within range. If your base is outside the alliance furnace radius, you are missing free temperature. Teleport closer if needed
- Defend it during Beast Crisis events. This is not optional. If the alliance furnace goes down during a Cold Wave, multiple members can cascade into -20C lockout
- Coordinate placement with leadership. The furnace should be central to your alliance hive, not off to one side
- Upgrade it as an alliance priority. Higher-level alliance furnaces provide more heat over a wider area
Beast Crisis Defence
Beast Crisis events send waves of enemies to attack your Alliance Furnace. The waves escalate in difficulty.
- Garrison the Alliance Furnace with your strongest squads before the event starts
- Coordinate with alliance members — do not assume someone else will handle it
- Bring both squads if you have two strong ones
- Losing the alliance furnace has consequences that last well beyond the event itself
- Treat Beast Crisis with the same urgency as an alliance war
War Buildings
War Buildings unlock at Furnace Level 30. They provide combat damage buffs for specific troop types.
War Building Strategy
- Rush Furnace 30 to unlock these. The +15% damage buff is massive and applies to all PvP and PvE combat
- Build the War Building for your primary squad type first — you want the damage bonus on your strongest squad
- Build your secondary squad's War Building second — the buff applies to rally contributions too
- War Buildings are one of the strongest late-season power spikes. Alliances where most members have Furnace 30 with active War Buildings have a significant combat advantage
Heat Stacking: How to Stay Warm
No single heat source keeps you safe. You need to stack multiple sources simultaneously.
Heat Source Summary
The Heat Stacking Principle
Think of your temperature like a budget. Each heat source contributes income. Cold Waves and environmental drops are expenses. You need your income to exceed your expenses at all times, with a comfortable margin for emergencies.
- Furnace alone is not enough during Cold Waves
- Furnace + Alliance Furnace keeps most players stable in normal weather
- Furnace + Alliance Furnace + Captured Cities keeps you safe during moderate Cold Waves
- All sources active keeps you comfortable through severe Cold Waves
If any single source drops out — your alliance furnace goes down, you lose a city, or you run out of coal — the others need to cover the gap. Build redundancy into your heat strategy.
Coal Management
Coal keeps your furnace running. If your furnace has no coal, it produces no heat. This is a daily management task that you cannot automate or forget about.
Coal Sources
- Gathering on the map — coal nodes appear throughout the frozen landscape
- Events and rewards — many Season 2 events reward coal
- Alliance supply activities — some alliance events provide coal
Coal Strategy
- Gather coal constantly. Always have at least one march on a coal node
- Stockpile coal before Cold Wave events — you will burn through it faster when temperatures drop
- Do not wait until your furnace runs out to start gathering. By then you have already lost temperature
- Keep a minimum reserve at all times. Running out of coal even briefly can push you below -20C during a Cold Wave
Running out of coal is the most common preventable disaster in Season 2. Your furnace does nothing without fuel. Set a minimum coal threshold for yourself — say, 24 hours of burn time — and never let your reserves drop below it. Treat coal like food for your troops. If they starve, they cannot fight.
Temperature and Virus Resistance
The furnace provides a second benefit that many players overlook: virus resistance. Higher furnace levels increase your resistance to virus-type enemies, which appear throughout Season 2 content.
- Virus resistance directly improves your combat performance against Season 2 PvE enemies
- This stacks with other combat buffs from gear, research, and heroes
- Players with low furnace levels take significantly more damage from virus enemies, making PvE content harder than it needs to be
- Another reason to prioritize furnace upgrades above everything else
Cold Wave Preparation Checklist
When a Cold Wave is approaching:
- Check your coal reserves — ensure at least 24+ hours of burn time
- Confirm you are within Alliance Furnace range — teleport closer if needed
- Coordinate alliance defence for Beast Crisis — the alliance furnace must not fall during a Cold Wave
- Top off your furnace fuel — do not enter a Cold Wave on empty
- Avoid teleporting to remote locations — stay near heat sources
- Have your strongest squads ready for Beast Crisis defence — pre-position them
- Check that captured cities near your hive are still held — losing a city during a Cold Wave compounds the temperature drop
Common Temperature Mistakes
- Ignoring furnace upgrades early — players who delay furnace upgrades spend the mid-season locked out during Cold Waves and never catch up
- Running out of coal — the number one preventable cause of -20C lockout
- Sitting outside Alliance Furnace range — free heat that you are missing because you did not teleport
- Not defending the Alliance Furnace during Beast Crisis — losing it hurts every nearby alliance member
- Building War Buildings before reaching Furnace 30 — you cannot build them until Furnace 30 anyway, but some players waste resources on other buildings instead of pushing furnace levels
- Only relying on one heat source — no single source survives a Cold Wave alone. Stack multiple sources
- Not researching temperature nodes — permanent temperature bonuses from research are easy to overlook but valuable over the full season
Related Guides
- Season 2 Overview — the full Season 2 primer
- City Capture & Rare Soil Strategy — captured cities provide temperature AND Rare Soil
- Season 1 HQ Guide — what to complete before entering Season 2