While buying diapers on the weekend from my muslim neighbors, I learned that the holy month of Ramadan has just recently started. The hot weather made me realize that Ramadan fast cyclicly varies from an easy obligation to one which is very hard. Fasting in summer implies abstaining from drinking while it's hot, and fasting for more hours a day. In fact, a muslim living north of the arctic circle would not survive a summer Ramadan, implying that no muslim can permanently live in arctic (or antarctic) regions. It also made me think about the Yom Kippur fast which turns out to be ideally placed in the autumn.