The Furnace Coat is a piece of Nightmare Unique armor with no boss attached: it drops anywhere in Nightmare, most often from N9 up (rarer below that home difficulty, never above it), and nowhere else. Every copy is item level 100, and there 0.3% of what falls comes up Unique. It is built on Exalted Wyrmscale Mail — step 6 of the Wyrmscale Mail line, item level 80 and up.

It always rolls the same numbers: +120 Armor, +436 Maximum Health, +140 Armor, +260 Armor, +594 Maximum Health and +45% Melee Damage.

One Unique drop in 40 is a Mythical copy: the same item carrying 15–25% Mythical Energy that boosts every stat on it and can never be changed; the 15% floor is 10 times as common as the perfect 25%.

On top of that it carries The Furnace Coat — Your hits apply Burn; +10% Armor.

It leans into Burn.

“Warm to the touch. Hot to the enemy's.”