With a forecast for lower temperatures on Yom Kippur, fasting this Shabbat should be easier, but experts say that heavy coffee, cola, cocoa or non-herbal tea drinkers should decrease their intake now to reduce the risk of headaches from caffeine withdrawal.
All adults and youngsters who plan to fast should drink more water than usual to “fill up their tank” and reduce the risk of dehydration and fainting, they add. But people who have an acute or chronic medical problem, take medications or underwent surgery recently as well as pregnant women should consult with their personal physicians (and rabbis, if they are observant) before Yom Kippur to learn whether they can fast or not."