At Madison High School in Vienna yesterday, staff members arrived early to open windows and let in a breeze at the Fairfax County school. Some teachers cut down classroom lighting and brought in fans.

"The only times it gets bad is on days like today with high humidity," Madison Principal Norman Bradford said.

But Madison freshman Beth Colgold, who sat outside drinking a soda and planning a swim in the family pool after school, said that nothing helped beat the heat in her afternoon Spanish class, taught in an upstairs room facing the sun.

"It's horrible," she said. "I don't think I work real well when it's hot."

Like dozens of schools in the Washington area, Madison, built in 1959, opened before air conditioning became a standard feature in new buildings. Yesterday's weather -- temperatures in the mid-80s, humidity nearing 60 percent -- made those schools steamy even for the most tolerant. In the District, one school closed because of air-conditioning problems.

Educators agree that learning suffers in sweltering temperatures, and growing numbers of parents are lobbying for air conditioning in their children's classrooms.

But some teachers and school officials question whether such an expensive item is a necessity in an area where classrooms heat up only a few weeks during the regular school year. By one estimate, the equipment alone costs $200,000 for a typical school, not counting labor and the renovations needed to adjust old schools to new technology.

"I would question whether it would be worth it for the amount of time it would be used," said Thomas Lamb, a second grade teacher at Woodley Hills Elementary School in Fairfax County.

Arlington teacher Bonnie Pfoutz says she disagrees. When she arrived in her Wakefield High School classroom one recent Monday after a hot weekend, the temperature was 92 degrees.

Pfoutz turned on a fan and waited. After an hour, it was down to 90. "You just sit and sweat," Pfoutz said. "It's too hot to do anything else."

Neither Wakefield nor Madison is likely to get full air conditioning soon: Fairfax and Arlington counties have policies calling for it in new schools, renovated sections of old schools, rooms such as offices that are used year-round, and group areas such as libraries and cafeterias.

Prince George's County and the District have similar policies. Montgomery County tries to air-condition the entire school even if only a portion is renovated.

The Fairfax County school staff in the past has urged full air conditioning in renovated schools, but the School Board said no, citing a rejected 1977 bond referendum for $5 million in air conditioning at 16 schools undergoing renovation.

Having air conditioning is not always the blessing teachers and students might think. In the District yesterday, 550 students were sent home from Fort Lincoln Elementary School shortly after noon because a water pipe in the air-conditioning system burst, damaging ceilings and flooding several rooms.

One school official said the school has closed three times in three weeks because of problems with construction. School spokesman Janice Cromer said city public works crews worked on the building last week and that one weld apparently did not hold.

"You do have to be concerned about your operational costs," said Andrew Weeks, the District's acting director of buildings and grounds. He said air-conditioning an old building often requires extensive renovations.

Weeks said old buildings -- with 15-foot ceilings, and large and plentiful windows -- were built to take the heat. "You can be rather cool in there," Weeks said.

Still, some educators say they are feeling more pressure these days from parents who do not want to send their children from homes that have air conditioning to schools that do not. "I think a lot of parents consider it a necessity instead of a luxury," said Mark F. Krause, clerk of the works for the Alexandria schools.

In Fairfax County, the PTA at Marshall Road Elementary School is taking matters into its own hands and trying to raise $21,000 to air-condition seven upstairs classrooms. "My third grader comes home and he's just wilted," said Priscilla K. Boyle, PTA president.

PTAs must obtain county permission to install air conditioning, and they must meet certain standards.