Upgrade Warmth when cold is the first thing that stops a useful Mine a Mountain run. The official description says the top is cold and explicitly lists Warmth as an upgrade. It does not publish exact levels, altitude thresholds, item names, or freeze consequences, so use the live warning and repeated routes instead of a fixed chart.
Recognize a Warmth blocker
Cold is the blocker when a warning forces you down while the Backpack still has space and the Pickaxe is clearing the route at a workable pace. If the bag fills first, capacity is the earlier issue. If mining one layer consumes the safe window, Pickaxe performance may be the earlier issue.
Record the highest point you can reach and still return safely. A failed freeze at the highest point is less useful than a repeatable turn-back landmark with a completed sale.
Set a retreat trigger
Choose a visible warning state or route landmark before leaving base. Turn back when it appears, not after movement becomes desperate. Keep enough time for the descent, seller interaction, and any detour created by mined terrain.
After a Warmth upgrade, repeat a similar route and use the same trigger. A useful purchase should extend the safe window or let you return with more margin. Exact temperature units or timers should come from the current UI, not a fan estimate.
Compare Warmth with other upgrades
The Upgrade Order Guide applies this comparison across the account.
Plan a higher route
Scout the current hourly mountain with a light Backpack. Find a stable ascent, first cold landmark, tool gates, and the return line. Improve Warmth only after the route is otherwise practical. On the next run, carry selectively so capacity does not hide whether Warmth improved.
Do not trust fan pages that name a universal summit item or minimum level without current game evidence. The Summit Guide uses readiness checks instead of unsupported gear names.
Include Runes and paid boosts in the record
Community documentation reports a temporary Warmth Rune, and the official Starter Pack description lists three free Warmth upgrades. These modifiers can change the test. Record them before comparing two runs. The exact Rune effect and timer are community-reported and need in-game confirmation.
No Fall Dmg and x2 Speed may change route risk or travel time, but neither official description says it replaces Warmth. Keep cold survival as its own condition.
Recover from freezing
The exact consequence of freezing—damage, slowdown, forced retreat, respawn, or item loss—must be observed in the current version. Until it is known, protect valuable inventory by turning back early. If a test fails, shorten the route, sell what can be secured, and compare the next Warmth purchase with live cost.
Do not use an exploit to suppress cold. The official experience warns that cheating and unauthorized software can lead to a permanent ban.
What still needs in-game testing
Warmth levels, cash costs, temperature thresholds, altitude bands, warning sequence, recovery, death or item-loss behavior, Rune stacking, pass interaction, and reset behavior all need current-server testing. This guide publishes the decision framework because the official core mechanic is clear while keeping unsupported numbers out.
Run a two-attempt Warmth comparison
Choose one route with an obvious landmark and begin both attempts from the same base area. On the first attempt, record current Warmth, any Rune or paid boost, time to the warning, highest safe landmark, and whether the return succeeded. Buy only one Warmth improvement, then repeat without changing Pickaxe or Backpack if possible. The useful result is the extra safe route time or altitude, not an assumed hidden temperature number.
If the second attempt also changes Weather, server layout, movement boosts, or the route itself, mark it as non-comparable and try again later. Do not sacrifice a valuable Backpack load just to finish the test. A Warmth purchase is successful when it reliably opens a profitable section or protects the return; if it only adds unused time while mining or capacity remains blocked, direct the next cash toward that other limit.