Certain biomes in Subnautica 2 will kill you before you even realize what hit you. The high-temperature zones lock off some of the game's best resources behind a specific Adaptation, and if you try to push through without it, you won't last long. The good news: getting the Heat Tolerance Adaptation follows a clear progression path once you know what to look for. Here's exactly how to do it.
What is the Heat Tolerance Adaptation?
Adaptations in Subnautica 2 are upgrades tied to large, plant-like structures called Angel Combs. Each one grants a passive biological upgrade that lets your character survive conditions that would otherwise be fatal on this alien world. The first Angel Comb you encounter is already open, giving you the ability to eat the local fauna and flora. The second one is where Heat Tolerance comes from, and it requires a bit more work to unlock.
How to unlock the Heat Tolerance Adaptation
Unlocking Heat Tolerance comes down to cleansing the second Angel Comb of its Bloom Infestation. Unlike the first Angel Comb, this one is sealed shut by the Bloom and won't open until you clear it.
Sonic Resonator clears Bloom
Here's the step-by-step process:
- Obtain a Sonic Resonator. This is the tool required to destroy Bloom Infestations. You'll need to track one down before you can interact with the second Angel Comb at all.
- Locate the second Angel Comb. It will be visibly covered by the Bloom Infestation.
- Use the Sonic Resonator on the Bloom. This destroys the infestation and opens the Angel Comb.
- Interact with the Angel Comb. Once cleansed, it grants you the Heat Tolerance Adaptation automatically.
Don't attempt to explore high-temperature biomes before unlocking Heat Tolerance. The heat will drain your health rapidly, and the resources there aren't worth a death run.
Why do you need Heat Tolerance?
Heat Tolerance isn't optional if you want to progress through the tech tree. Two of the most important late-game resources, Gold and Sulfur, are found exclusively in high-temperature areas. Both materials appear regularly as crafting requirements as you push deeper into the game's technology progression.
Beyond raw resources, these hot biomes also contain new wrecks and scannable objects that expand your blueprints and knowledge base. Skipping them means hitting a hard wall on crafting options.
Gold and Sulfur are not available in cooler starting biomes. Heat Tolerance is the only way to access them.
For players just getting started, our Subnautica 2 beginner's guide covering oxygen, scanning, and base building covers the foundational systems you'll want solid before tackling the Bloom Infestation.
Gold only spawns in hot zones
How does this fit into the broader progression system?
Adaptations are one of the more interesting design choices in Subnautica 2. Rather than gating progress behind gear upgrades alone, the game ties exploration access to biological upgrades earned through story-adjacent objectives. Cleansing Angel Combs is effectively the main progression loop for unlocking new environmental access.
This system is one of several new features introduced in the sequel. For a full breakdown of what's changed from the original game, the confirmed new features for Subnautica 2 Early Access covers the Adaptation system alongside co-op, the new planet Zazura, and vehicle changes.
Once you have Heat Tolerance, prioritize scouting wrecks in the hot biomes. Scannable objects there can unlock blueprints you won't find anywhere else in the early game.
For more on surviving and thriving in one of the most anticipated survival games of 2026, check out the full Subnautica 2 guide collection for tips on every system the game throws at you.