The 25-hour Yom Kippur fast is not an easy one, particularly when the weather is hot.
In addition to abstaining from food, traditional Jewish observance of the fast includes abstaining from water. Many Jews even avoid brushing their teeth or taking non-essential medicines, in order to comply with this prohibition.
If you are planning to observe the fast fully, experts recommend drinking extra water in the days leading up to the fast. Find more tips for staying healthy during the fast here.
However, if going 25 hours without water is going to make you sick, you should not do it. Jewish law exempts from the fast children under 13, pregnant and nursing women and those for whom fasting will endanger their health. Learn more about who is and is not traditionally required to fast here.