Creatures of Ava allow you to permanently upgrade three aspects of Vic's gear: stamina, backpack size, and health.
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The game features four unique biomes: Tamura Grasslands, Nari Jungle, Maruba Swamp, and Antar Dunes. You must find Health Kits in different parts of each biome to increase your maximum health in Creatures of Ava.
You’ll start your journey in the Grasslands, unlocking other biomes as you complete all of the quests in the region. Various infected and feral creatures will attack when you’re near them, so increasing your maximum health will make survival easier. We found Health Kits in all of the biomes except Antar Dunes, with most kit locations requiring you to progress the story to unlock regions. Once you complete all of the Nari Jungle quests and move on to the next biome, you won’t be able to return to collect the permanent upgrades. However, you can use the Teleporter to travel and collect the upgrades in other biomes whenever you want.
Here are all the Health Kit locations in Creatures of Ava.