Being on the top floor of a building without A/C can definitely be an issue with respect to heat.
However, while having to lug a bunch of groceries (or whatever) up multiple flights of stairs can be an pain, is "walking up 5 flights of stairs a day" really a big issue? [Obviously for some people with infirmities it will be.] I work--well, when I commute--in a 4 story office building and most people, including myself, take the stairs when we move between floors for meeting, cafeteria, etc. We at least used to have signs encouraging taking the steps.