Hi, if i live in an extreme heat climate, am i allowed to drink water on fast day?

Shalom, Thank you for your question. In general, the laws of fasting including refraining from both food and drink, including water. So, the simple answer to your question is that drinking water on a fast day is forbidden. However, there is an overriding principle that applies to fasts. That is that one’s health is more important than the fast. So, if refraining from drinking will cause a person to become ill (bedridden; sick; unable to function normally etc), then one does not have to fast, and should drink water (and eat and drink anything else that is needed). This could well be the case in a very hot climate if you must be outside. The laws of Yom Kippur are stricter, and the level needed to allow drinking is higher. That is, if on a “minor fast” any level of sickness cancels the fast, on Yom Kippor this is allowed only when there is a possible danger to life. We are very careful when defining this, and dehydration is certainly a life-threatening condition that must be avoided. There are also laws for Yom Kippor about how to drink the water when it is allowed (small measures with pauses between). On the other fasts, when drinking is allowed, it may be drunk in a normal fashion. I hope this is of some help, Blessings.