Ever wonder why Van Gogh wore that straw hat? A good guess would be it kept him from fainting under the summer's blazing sun as he stood outside all day painting the streets and fields of Provence.

Just like Van Gogh, artists with hats have been setting up their easels all over Washington, trying to bear the heat as they capture sun-baked scenery on their canvases. They've been spotted along the C & O Canal, in downtown Bethesda, on the National Cathedral grounds and even on the stairwells and rooftops of parking garages.

Who are these brave souls? They are the 90 or so art students, from teens to seniors, enrolled in an outdoor landscape class conducted by Walter Bartman, a teacher who they apparently will do anything for, including standing on a street corner with a paint brush for four hours on a Code Red day.

Artist Joanie Grosfeld, however, says she learned her lesson after roasting on the banks of the canal. This time she chose a spot under a restaurant awning.

Like many of the painters, Grosfeld has to deal with thirst, mosquitoes, and, yes, kibitzers: "People will stop and look at my painting and say, `It looks like Paris.' Or they'll say, `Bethesda never looked that good.' " Grosfeld doesn't mind the comments, she says, especially when she was at the Cathedral and was cheered on by a priest who faithfully checked her progress.

At the intersection of Woodmont Avenue and Old Georgetown Road, Fred Pelzman, another art student, is having more than the usual distractions. Parents point the painter out to their children, who stand transfixed, looking at how this grown man is making a beautiful picture of buildings and traffic lights.

One mother can't resist a comment: "You should put people in there," she says, pointing to the lower half of the painting. "You remind me of my wife," Pelzman kids her. A few minutes later she returns with her husband and children and tickles Pelzman's neck with a fern she has plucked from out of nowhere. "You still haven't put people in?" she asks, playfully. Without missing a stroke, Pelzman just grins and paints his buildings.

Minutes later a man rushes up to Pelzman and excitedly asks, "Did you see that accident that almost happened . . . right here on the corner?" No, says Pelzman, he didn't. "Didn't you hear the squeal of the brakes just seconds ago?" the man asked, incredulous. "Oh, yes, I guess I did," said Pelzman, "but I didn't look." Not appeased, the man nearly pokes the canvas, and points to the empty intersection in the painting: "You should paint the car right here!" he says loudly, then rushes on, leaving the artist nonplused.

Pelzman, a government retiree and part-time tour guide, has a passion for painting, which he greatly attributes to his teacher. "I paint with Walt (Bartman) because he gets me out of the studio: There's a whole world out there to paint."

Walter Bartman, director and founder of the Yellow Barn Studio in Glen Echo, has been conducting these outdoor classes since 1982. His students may be aiming for a career in art, or they are there simply to improve their avocation.

No matter what their goal, they are so focused on the assignments he gives (and he paints right along with them, withstanding the heat) that they don't complain about the weather conditions. Last week, on the final day of their classes, Bartman spent hours giving critiques to the assembled students in the large studio on the Glen Echo Park grounds. One by one the students faced their classmates to display their paintings of the Washington area as seen through their eyes.

Monica Perdomo, who is from Cuba and heading for the Rhode Island School of Design this fall, is fretting that she is late as she carries her stack of paintings. They are stunning, all done in a powerful, semi-abstract style, as if she saw the city streets and parks through an explosion of broken, colored glass. "For a long time no one understood them, now they do," says Perdomo, proudly.

How could she paint so beautifully in such hot weather? "Actually, the worst days are the best for painting," she explains, "because the light is better."

Bartman praises the group, for two reasons in particular: "We suffered through the summer from hell. You persevered. The landscape is incredibly difficult, it is changing by the second and you had to make sense of the light."

For information on year-round landscape classes, including winterscapes: 301-371-5593.