Soaring mercury becomes a hazard

Brutal temperatures bring grid brownout, higher death risk

August 09, 2007|By Frank D. Roylance and Chris Emery | Frank D. Roylance and Chris Emery,SUN REPORTERS

Temperatures soared to 105 degrees in downtown Baltimore yesterday, turning up the burner on what was already the worst heat wave of the summer and forcing a brownout on the region's power grid.

The high of 102 at Baltimore-Washington International Thurgood Marshall Airport scorched the previous record of 99 degrees for an Aug. 8, set in 1980. It was the hottest day at the airport in more than eight years. Downtown, heat index readings rose to about 120 degrees.

There were no immediate reports of deaths in Maryland linked to this latest siege of hot weather. Thirteen Marylanders have died this summer from illnesses triggered or exacerbated by high temperatures, only one of them in Baltimore.

In at least 11 of those deaths, the victims already suffered from cardiovascular disease, according to the state office of the chief medical examiner.

Intense heat across the Mid-Atlantic states proved so taxing to the region's power companies that the PJM Interconnection, which manages the grid, ordered a 5 percent voltage reduction about 4 p.m., the first in two years. The voltage cutback affected millions of customers in the Mid-Atlantic portion of the grid.

"A 5 percent voltage reduction is virtually undetectable by customers," said BGE spokeswoman Linda Foy. "It typically reduces demand by 2 or 2 1/2 percent, so it helps keep the system balanced."

PJM also asked customers to conserve. That triggered power-saving plans among some of the system's largest consumers, including the state office complex in Baltimore.

"Under an agreement with PJM under such emergencies, the Baltimore State Government Complex at Preston Street engaged two engine generators which shaves 2.4 megawatts off the grid," said Dave Humphrey, spokesman for the state Department of General Services.

It was a drop in the bucket. Yesterday's electric consumption numbers were not immediately available, but on Tuesday, BGE customers set a summertime power consumption record, using 6,739 megawatts. A typical hourly peak in summer is 5,500 megawatts.

Power outages yesterday made cooling off more difficult for more than 8,000 BGE customers. Foy said it was too soon to determine the cause.

The worst of the heat might be behind us. Forecasters said the high today would reach the mid-90s, with a slight chance for a thunderstorm to dilute the sweat.

Conditions should improve as the weekend approaches, the daily highs slipping to the low 90s tomorrow and the high 80s from Saturday into next week.

Yesterday was the eighth day in the past nine with temperatures of 90 degrees or more, and the 27th day of 90-plus weather this summer.

The high temperature at the Maryland Science Center in Baltimore's Inner Harbor was 105 degrees. The last time BWI saw a high of 102 was July 5, 1999, according to the National Weather Service forecast office in Sterling, Va. Records were also set at Ronald Reagan Washington National Airport in Washington (102 degrees), and Washington Dulles International Airport in Northern Virginia (100).

The weather service posted heat advisories nearly statewide for Maryland yesterday. Baltimore extended its Code Red Heat Alert into today, opening 10 cooling centers across the city.

As hot as it has been, deaths from heat-related causes this summer, with three weeks to go, do not rival those from recent years.

There were 42 deaths last year, and 47 in 2005. The drought summer of 2002 saw 50 heat-related deaths across Maryland.

In summers with cooler weather, heat-related deaths have numbered as few as three (in 2003).

Eleven of the 13 dead this season have been men. Their ages ranged from 39 to 82, averaging about 58 years. State and local officials were unable to provide their names.

Perhaps surprisingly, the largest number of deaths this year has not been among the poor and homeless in Baltimore, as has been the case in recent years. The city has reported only one heat-related death, an unidentified homeless man found July 16 in a vacant building.

Somerset County, too, has reported just one heat death. Baltimore, Montgomery and Cecil counties have had two each.

The rest -- five deaths -- have occurred in Prince George's County, according to the state health department. They include:

A 77-year-old man found unresponsive in his yard in 90-degree weather May 29. The Office of the Chief Medical Examiner ruled that the primary cause of death was "hypertensive artherosclerotic cardiovascular disease, complicated by hyperthermia." That means he died from the effects of clogged arteries and high blood pressure, made more acute by the heat.

Another 77-year-old man, with the same diagnosis, was found June 9. He was in his car in a parking lot. Outdoor temperatures were in the 90s.

A 53-year-old man, with the same underlying disease, became overheated while working in his yard June 26. He went to his car, where he was found later, unresponsive. Temperatures were in the 90s.

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