In Jain practice, the ideal is to drink water before sunset and plan ahead so you are not forced into that situation.

If it is already after sunset:

• Try to avoid drinking if it is only for comfort, especially if you are observing strict vrata or restraint.
• If thirst is severe, or there is a health concern, Jain Dharma places great value on preserving life and health. In such a case, many follow a practical and compassionate approach and take water mindfully.
• If you have taken a specific vow, follow your own vow’s rules and the guidance of your guru or ācharya.

For future nights:

• Keep water ready before sunset.
• Drink enough in the evening.
• Avoid salty or very dry foods late in the day.

The Jain spirit here is balance: self-restraint with non-violence and care for the body.