Status ailments such as Burn
can be afflicted by various enemies. As such, it’s recommended to always have some recovery items at hand such as Antidote Powder, Dousing Powder and Contact Medicine. These can be acquired as world loot or purchased from the Battlefield Memorial Mob
You won't get poisoned immediately until the poison gauge gets filled up completely. Poison is a lot dangerous since its effect will linger long after it is inflicted on you. While in effect, you will steadily lose HP. It’s possible to wait for the effects to wear off but you’ll lose a lot of HP. If you still have one resurrection charge and you’re in a safe location (and want to save up your supply of Antidote Powders), you can just let it kill you to remove the effect then resurrect to heal up.
Burn is not applied immediately; if you get hit by a torch or fire arrow, you’ll get a burn buildup meter, even if you're blocking it. If that gauge gets filled up, you’ll acquire the burn status, which will prevent you from recovering posture and will have the same HP draining effects of Poison. You need to use Dousing Powder to treat it. A unique, reusable item called the Withered Red Gourd can be purchased using Treasure Carp Scales from the Pot Noble Harunaga
in Hirata Estate. While this doesn’t heal the burn status, it will reduce burn buildup and your burn resistance.
Beware of Oil
There are enemies that will throw oil at you. Once you're soaked in oil, you'll get burned more easily. Oil cannot be removed by ordinary means like jumping in water. Resting at a Sculptor's Idol however, completely removes the oil.