Health, as one would expect, is a very important resource in a monster-hunting game, such as Wild Hearts. Players can't see the Kemono's health, but they can see their own. At the start of the game, Kemono attacks hurt, sure, but it's really only their attacks with the gigantic windups that are 'truly' dangerous.
But, as things progress, especially in Chapters 4 and 5, even a single hit could be dangerous without proper preparation. And, while there are plenty of ways to increase armor, elemental resistance, evasion options, or even gain temporary health, permanent health is another thing altogether that a lot of newer players seem to be overlooking. So, let's go over exactly how players are meant to permanently increase their HP in Wild Hearts.
Tamakazura's Bathhouse
The main method by which players are able to increase their max health is through Tamakazura's Bathhouse. Unfortunately, when they first reach Minato, the Bathhouse is closed, and Tamakazura is pretty dejected about it. But, once the player, somehow, manages to beat the sentient bear-mountain AKA the Earthbreaker, the Karakuri that makes the Bathhouse function is rebuilt, and Tamakazura has a job again.
Now the primary function of this Bathhouse will be described below, but it's worth mentioning that this place also has a secondary role, it cleans the hunter and their armor. A bit odd, considering the hunter leaves their armor with Tamakazura before going in, but they'll notice coming out that it looks shiny and clean. Some players may not have noticed, but there actually is a dirt and grime system in the game that seems to build from players going on a bunch of hunts or fighting specific Kemono without bathing in between.
How To Use To Bathhouse
As soon as this freshly-built Bathhouse becomes accessible, players are able to use it and develop new restorative baths. Each one will require different materials or components to craft, and each bath will have different little 'garnishes' added to the water such as tropical fruit or Tsukumo (for some reason). And, after the player develops the new restorative bath, a cutscene will play showing them relaxing as a result of their work and in the result of their work. This is where a player's max HP increases, and after this initial bath (for each option) players can use each individual bath as often as they want, but it won't buff their health anymore.
Keep in mind that the materials required to craft these baths are not limited to one 'type' of gatherable. Some of them will require basic Minerals found around the maps, some will require items harvested from or gifted by Creatures or Small Kemono, and some even ask for Giant Kemono item drops. After managing to restore every single bath (of which there are about 6) players will receive the 'Bewitched by Bathing' achievement/trophy as a result.
Other Methods Of Max Health Increase
And, it's also worth mentioning the two other methods for players to increase their Max Health (albeit temporarily) with Skills and Food. Skills are essentially 'permanent' Max HP upgrades, as they'll last as long as the player wears whatever set of armor has the Health Boost Skill on it.
This Skill can stack with itself as well as with the other boosts that come from food. Eating, on the other hand, is only temporary but makes a massive difference before a Kemono battle. In the late-game especially, forgetting to eat food with Health Boost before a Kemono battle is basically asking to get KO'd almost instantly.
Wild Hearts is available now on PS5, Xbox Series X/S, and PC.