Thirst depletes over time, and it depletes faster when you're hot. If your thirst is fully depleted, you'll start taking tick damage similar to hunger.
Keep an eye on your thirst bar and drink regularly to avoid the negative effects of dehydration.
To manage your thirst, the best option is to drink water. You can use water bottles or the newly introduced Water Flask.
You can also use a Moisturizing Talisman to slow down thirst depletion by 50%. For the effect to activate, the talisman needs to be in your inventory.
Some food items can also replenish a percentage of thirst.
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For more details on how to replenish your thirst, check out Hydration Values.
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