In Biomutant, Hypoxia is a status effect that is caused by environments that are too hot, causing a lack of oxygen. When entering these environments players will see a percentage value in the top right corner of the screen. It will count down over time, and when it reaches 0% the players will start taking damage. Players will continue to take damage until their health is entirely depleted.
To survive in these environments, players can equip armor with good Hypoxia Resistance values. All armor items in the game will provide differing degrees of protects from the different hazards, and players can put on armor that offers decent Hypox protection.
It is entirely possible to put on armor that can, when all the values are added up across all the armor pieces, provide 100 percent protection against Hypoxia. Players can also complete a mission called The Oxygen Pingdish, located to the very north of the Tree, that will tune a pingdish to give them the location of the Oxygen suit.
The Mekton can also be worn in Hypoxia areas that are big enough to allow it, and it will completely protect players from the effects of Hypoxia. The final way to protect yourself from Hypoxia, or any other hazard type, is to spend Biopoints on those resistances in the character menu.
These are earned each time you level up, and can be spend on a variety of stat or ability increases in the character menu.