A few days with temperatures in the high 90s have already taken a toll in Maryland, and forecasters warn that the week ahead will only get worse.
The National Weather Service said the mercury will bubble close to or beyond 100 degrees today and tomorrow. High humidity will further impair everyone's ability to cool off, as "heat index" readings soar above 110 degrees.
Around the region, officials issued heat alerts, closed the Maryland Zoo in Baltimore, opened cooling centers and asked residents to check on the elderly, sick and frail in their neighborhoods.
The heat was already making life miserable Sunday at the Broad Creek Memorial Scout Reservation in Harford County, where Polish-speaking Scouts who had assembled from cooler climes - such as Sweden, Poland and Canada - began to swoon as temperatures hit 96 degrees.
"These people just flew in from around the world on Saturday. They're not used to our temperatures. They're not used to our humidity," said Reed Blom, director of camping services.
Harford County paramedics took nine participants to area hospitals, where they were treated for heat exhaustion and released. Another 40 - ranging in age from 14 to 65 - received treatment at the camp.
In Carroll County, a 76-year-old woman suffering from dementia wandered off into the heat yesterday, triggering a search that involved a State Police helicopter and bloodhounds.
Less than an hour after she disappeared, the woman was found by her brother, who reported that she was sweaty but unhurt in a cornfield. She had fallen, he said, and couldn't get up amid the 5-foot-tall cornstalks. A drink of cold water set her right again.
"I'm not gonna let her out of my sight for a couple more days," the man said.
As hot as it has been, the outlook for the balance of the week is even hotter. Yesterday the National Weather Service posted an "excessive heat warning" for most of Maryland from Washington County eastward through 6 p.m. Thursday.
Temperatures could top 100 degrees today and tomorrow, flirting with or breaking records more than a half-century old. The record highs at Baltimore-Washington International Thurgood Marshall Airport for today through Thursday, respectively, are 99, 100 and 100 degrees.
The predicted highs for today were 99 degrees at the airport and 103 at the Inner Harbor. A 100-degree reading at BWI would be the first since July 4, 2002. The triple-digit forecasts extend through tomorrow at the airport and Thursday downtown.
Heat index readings could soar as high as 115 degrees in some locations, forecasters warned.
There's a chance for thunderstorms by late Thursday or Friday as a "cold" front pushes through. The airport high Friday is forecast at 88 degrees, with 90 expected in the city.
Real relief isn't likely to arrive until the weekend, with highs Saturday and Sunday in the mid-80s.
"Definitely on Saturday we'll see refreshing air. You're going to notice the difference," said Luis Rosa, a forecaster at the weather service's office in Sterling, Va.
From West Coast
Marylanders can blame California for sending us its hot weather. The same high-pressure system that stalled over the West Coast states last week, producing record temperatures, began moving east over the weekend.
"It's going to be drifting to the east and positioning itself over southern Virginia Wednesday, and that's going to bring us hot temperatures," Rosa said. "Thursday will be nearly as hot as Wednesday."
BGE said late yesterday that its consumers had not yet broken the utility's usage record of 7,045 megawatts, set July 26, 2005.
But as the heat drags on, officials said, high consumption across the 13-state regional power grid could trigger BGE's Energy Saver program. That's when BGE cycles the air conditioners and water heaters of enrolled customers through 15-minute shutoffs via remote control. Voltage reductions, also known as "brownouts," are also a possibility.
"As a last resort, the [regional grid] could require temporary service interruptions ... in order to protect the integrity of the electric system or reduce the risk of equipment damage," said Mark P. Huston, BGE's vice president for distribution, in a prepared release.
That would produce intentional blackouts in some areas.
As insufferable as the heat seems now, we have suffered through this before. "Every three or four years we get a heat wave like this," Rosa said.
For example, the summer of 2002 saw 44 days of 90-degree-plus weather at BWI from June 1 through Aug. 31, including one unbroken stretch of 11 August days with temperatures in the 90s. It was among the worst heat waves in recent memory.
The next summer, 2003, saw just 14 days in the 90s.
It's the humidity
This week's heat was simply too much for the Scouts who gathered in Harford County over the weekend. They quickly learned what Marylanders have known for generations: It's not the heat.
"The humidity was overwhelming," said Julian Minor, 17, who arrived here from London with his father and brother.