Here is a small plein air sketch I painted a few months back. At the end of April, I made a visit to the Portland (Oregon) area. On a frigid morning, I rode the Light Rail train into downtown P-town for a day of bumming around. When I arrived at 7am, I found that nothing was really open that early. So I sat in park and painted until the shops opened up. It was breath fogging, finger freezing, knee knocking cold! On the positive side, I didn't have to worry about my paint drying too quickly
Below is a picture of the set up I used. Out of all the tools in this picture, I'd have to say the most important was that cup full of warm caffeine. Very important indeed.