limitations

I'm intrigued by the way that increasingly, my reading here is bound by limitations that are purely physical: can I make it to and from the Library without getting overheated? How much can I carry at one time without becoming overburdened? How many books can I carry at once for four or five blocks? Is it possible to read as much as I need to read in the next eight days?
The answers: yes, so far, but it's been close once or twice;
my bookbag today has my laptop, the power cable, a long-sleeved shirt for the air-conditioned archives, at least five issues of various children's lit journals, a paperback book, and a hardcover book I borrowed from my advisor today;
I need to go pick up a dozen at the library tomorrow, so hopefully at least that many!;
no idea! But I will try.