one year, he was advised not to fast. but, he quoted the hadith of the master sallAllahu 'alaihi wasallam: fast so that you may gain health [soomoo tusaHHoo?]. he believed that people do not become ill due to fasting, rather they become healthy because of it.
because ramaDan in those years fell in summer; and summer in bareilly [uttar pradesh in general] can be very very hot [average 42C-47C] and long. as alahazrat was already unwell, it would have been difficult for him to fast on long and hot summer days. there were no A/Cs in those days; not even electric fans! so he moved to a hill station, which is relatively cooler and hence relatively easier to fast. Allah ta'ala knows best.
since ramaDan is upon us... in his later years before ramaDan, alaHazrat was advised not to fast due to illness. however, his taqwa did not allow this and he spent the whole month of ramaDan is a mountanous area where the fasting was easier [perhaps due to weather] and he didn't miss any fasts. --- i will post details of the whole incident when i can.