The Old Town Pool had to begin turning people away about an hour after it opened Monday, as it had already reached capacity.
A heat advisory is in effect for the entire D.C. area until 8 p.m. tonight, with temperatures expected to hover in the mid-90's, but to feel like anywhere from 100 to 105, with the heat index. Tomorrow's high temperature is also expected to be in the 90's.
Two schools in Fairfax County, Mount Vernon High School and Madison High School, are being dismissed at noon today because the air conditioning in the schools are not working. Baltimore public schools are also dismissing students at noon.
Health officials are reminding people to stay hydrated, limit time in the hot sun, keep an eye out for elderly relatives or neighbors, and make sure pets are safe.
Air quality can mean health problems
The Code Orange alert means pollution levels may be unhealthy for children or anyone with a breathing or heart condition.
Everyone can do their part to try to counteract a poor air quality day like today, says Harriet West, the managing director for Clean Air Partners, the group that issues air quality forecasts.
She says to minimize poor air quality people should drive as little as possible, resist topping of the gas tank, and consider waiting to mow the lawn until the air quality improves.
That's because the heat can amplify pollution in the atmosphere.
"Bascially some of the pollutants that are in the air become trapped, sunlight cooks them and creates elevated levels," she says.
tThe number of poor air quality days fluctuates from year to year, based on the weather.
West says the region had just four poor air quality days during the relatively mild summer of 2009. But that number jumped to 35 days during last summer's near-record 90-degree days.
Heat takes toll on vehicles
Beyond the heat's effects on people and pets, the Automobile Association of America for the Mid-Atlantic Region is also warning motorists about what the first wave of truly hot weather can do to their cars.
AAA's John Townsend estimates that his crews helped more than 33,000 stranded motorists over the course of the holiday weekend. But he warns that residents who didn't drive over the weekend may feel the effects of the heat this morning.
"Each day of extreme heat is cumulative, so chances are, service calls for dead batteries and cars that won't start will spike on the first day back from Memorial Day," he says.
Townsend says it's easy for people to be caught off guard by the first dose of extreme heat -- especially because they don't associate heat with difficult driving conditions.
"Extreme heat has as much negative impact on automobiles as extreme cold," he says.
Most summer breakdowns occur because of battery-related problems, according to Townsend. Every car owner should make sure their battery terminals are free of rust, and that their battery is properly charged, he adds.
He also recommends having a kit with water, first aid supplies, and flares just in case of an emergency.
Pools are key to keeping cool
At the Old Town Pool in Alexandria Monday, pool-goers were quick to share their tips for keeping cool. The pool opened at noon on Memorial Day -- and within an hour it had reached its 250-person capacity, much to the disappointment of latecomers forced to wait outside the entrance until someone inside decided to call it a day.
Carrie Johnson, who arrived soon after the pool opened armed with cold drinks, she says the hot weather is a blessing and a curse.
"I don't know if anybody likes the heat, but we like the pool," she says with a laugh.
Inside the fence, 11-year-old Daevaughn Dyson complained that the sun-baked concrete was cooking his feet, but he had a simple solution for that.
"My strategy for staying cool is staying in the pool as long as possible," he says.
Joanne Maggi is a regular, and for her, visiting the pool is all about staying in the sun, as long as she can stand the heat.
"When I get too hot laying out here trying to get a tan and looking good I just go right in the water and stay there," she says. "And always keep plenty of water by your side."
Though the heat is likely to attract more crowds at public pools, many in the region will be out of luck as the heat wave continues through today and into tomorrow, as most of the area's pools are still open just on weekends.