Heat Resistant Undershirt

Details

It does not stack, so every spare copy costs an inventory slot. At 16,540 gold it is worth real money to a merchant.

Heat Resistant Undershirt Crafting Recipe

Wool×20

Flame Organ×15

Leather×25

Fiber×35

What it really costs, once every sub-recipe is expanded

Leather×25Wool×20Wood×18Flame Organ×15

Crafting it takes 95 materials across 4 types.

Where to Find Heat Resistant Undershirt

The recipe is not on the Technology tree — it is locked behind a schematic you have to find first. The best single source is treasure chests in the Feybreak at 3.4% per container, and the table below lists every tier and where each one drops.

The recipe above builds the plain copy. A Rare one exists as well, and it is not crafted from anything you can farm on purpose — it comes off the Heat-Resistant Undershirt Schematic (Heat-Resistant Undershirt Schematic), which only appears on grade 5 chest tables and only in Feybreak. Treasure chests inside Feybreak Cavern carry it at 3.45%, crates on the oil rigs at 1.18%, ordinary Feybreak chests at 0.19% — roughly 29 cavern treasure chests, 85 rig crates or 526 field chests per copy. Clear the cavern for it; the field chests are eighteen times the work for the same paper.

Using Heat Resistant Undershirt Well

Schematic or not, it goes together at the High-Quality Workbench, the same bench the Rare version wants, so nothing here forces a second gear base.

The heat line it carries is the same Heat Resistance Lv. 3 that Multiclimate Undershirt carries, so the Multiclimate Undershirt is not a warmer coat — it is this plus the cold half of Thermal Undershirt in one slot, and the game values it at 167,040 against 16,540 for this. That gap is the whole argument: build this while the desert is the only place you are getting cooked, and only move up when you are crossing between the volcano and the snowfield often enough that swapping undershirts between trips is costing you more than the Ice Organs and Polymer would.

What Heat Resistant Undershirt Does

Heat Resistant Undershirt grants Heat Resistance Lv. 3: Temperature Resist Heat +3.

Schematics That Unlock Heat Resistant Undershirt

Heat Resistant Undershirt is not learned from the Technology tree — you need a schematic for it. One schematic grants the recipe, and they are world loot — chests, boss Pals and the late-game pools — rather than anything you research. Higher-rarity copies of the same schematic raise the quality of what you end up crafting.

Fastest route. The top-tier Heat Resistant Undershirt schematic is worth hunting directly — treasure chests in the Feybreak is its best source, at roughly 29 containers a copy. Schematics fuse five-to-one, so a lower tier with better odds can beat the top tier outright. Counts are containers of that source, not time.

Schematic	Rarity	Where it comes from
Heat-Resistant Undershirt Schematic	2★	Feybreak treasure chests, Crates on the oil rigs, Feybreak chests — best 3.4% (grade 5)

Alternatives and Upgrades

Other accessorys at a similar tier, for when you want to weigh this against the rest of its class:

Dark Support WhistleElectric Support WhistleAttack PendantLife PendantPendant of DiligenceRing of Dark ResistanceRing of Electric ResistanceRing of MercyRing of Grass ResistanceGrass Support WhistleDefense PendantFire Support Whistle