First up, some tips from me to you for working outside:
Consider Cleanliness. Jolie Kerr, who writes the cleaning advice column "Squalor" for Deadspin and Jezebel, adds to the above, the "best tip I can give is to have a chamois and/or tech wipes in your laptop case—there's nothing like sunshine to reveal exactly how streaky, linty, cat-furry your monitor is! The natural light also makes it harder to see your screen, which a good cleaning will help vastly."
And then, an ode to Epstein's:
Also, as Kerr points out, indoors establishments have their own benefits: "I work from a bar rather than a park bench or the beach because a bar has wine," she says. "