NEW YORK, July 21 (Reuters) - Sweating crowds on the East Coast and in the Midwest flocked to waterfronts and urban cooling centers on Thursday to escape a massive heat wave that has killed at least 22 people this week.
The National Weather Service issued excessive heat warnings for wide swaths of the country's mid-section and East Coast, saying the combined heat and humidity could spike the heat index or "real feel" of the warmth to 115 degrees through Saturday.
By early Thursday afternoon in New York City, the thermometer hit 91 but it felt more like 112, according to Accuweather.com.
Other cities watching their local heat indexes rise into the triple digits because of the oppressive mix of high temperatures and humidity included -- among others -- Tulsa, St. Louis, Buffalo, and Washington, D.C., according to the weather service.
In Chicago, where a five-day heat wave in 1995 killed hundreds, the city endured a fifth consecutive day of abnormally high temperatures with the heat index hitting 110 in the early afternoon -- and forecasters warned the heat wave could continue into the weekend.
In Oklahoma, where the heat has exacerbated a severe drought, Governor Mary Fallin said she planned to ease commercial vehicle restrictions to speed delivery of hay and other feed to cattle whose grazing areas have been destroyed by the weather.
Fallin said she would amend an existing drought-related emergency declaration she issued earlier this year to allow hay-haulers to operate bigger trucks with heavier loads on the state's roads.
"We have cattle that are starving," Fallin told Reuters, "and we have certain areas of the state where we need to get the hay delivered to the farmers and the ranchers and the cattlemen."
With the promise of refreshing ocean breezes, Boston's whale-watching ships and high speed tourist boats sold out their trips by mid-morning on Thursday.
Cooling centers in Richmond, Virginia, and New York City welcomed overheated residents and a truck labeled "Water Fountain on the Go" cruised Manhattan streets, offering to refill empty water bottles to keep residents hydrated.
Con Edison expected scattered outages in coming days amid an anticipated all-time high in electrical demand in New York, said utility spokesman John Micksid.
Unhealthy smog levels triggered by the heat were reported in Chicago, where residents were asked by the Illinois Environmental Protection Agency to reduce polluting activities such as idling cars and mowing lawns.
By the weekend the heat was expected to cover nearly 50 percent of the country and impact nearly half the population, according to AccuWeather.com forecaster Mary Yoon.
"What makes this heat wave so impressive is the pure size and longevity," said Yoon.
"Through the rest of this week and into the weekend at least 15 states starting from the Southern Plains and Midwest and much of the Northeast will witness 90 degree plus temperatures with high humidity," she said.
Longstanding records in Philadelphia and other cities may melt away by Friday, when the mercury was expected to spike, according to meteorologist Meghan Evans of AccuWeather.com.
"Do not take this threat lightly," the NWS warned in a statement on its website, noting the extreme temperatures are particularly dangerous for the elderly and the very young.
"The length of this heat wave will pose a very real and dangerous health risk to these at-risk groups and those that do not have access to air conditioning."
The low pressure system that barreled east was expected to bring powerful thunderstorms with hail to New England, forecasters said.
In the central United States, where the high temperatures have killed nearly two dozen already, more deaths were tied to the heat.
An elderly woman whose body was found in her bedroom in St. Louis, where a working air conditioner had not been turned on despite 99 degree temperatures, was determined on Wednesday to have died of heat stroke.
Similar causes of death were reported Thursday in Kansas City, Missouri, where a woman in her early 80s died, and in Hutchinson, Kansas, where three elderly people were found dead in their separate homes on Wednesday.
Of those who died in Hutchinson, one had a ceiling fan and another, a 76-year-old man, an air conditioner.
"He had an air-conditioning unit in the window but didn't use it because he didn't want to pay the electric bill," said Hutchinson Police Sergeant Thad Pickard.
Two people died from the heat in an Illinois county near the Mississippi River on Wednesday, St. Clair County Coroner Rick Stone said on Thursday.
They were identified as Willie Gill, 72, of East St. Louis, Illinois, whose body was found dead of heat stroke in a ditch near his home; and Kevin Miller, 51, of Belleville, Illinois, who was found dead of a heat-related heart attack on his front porch, which faced westward toward the setting sun.
Temperatures in the area, which is about 15 miles east of St. Louis, reached 100 degrees on Wednesday and again on Thursday. (Additional reporting by Bruce Olson, Lauren Keiper, Kevin Murphy, Karin Matz, Colleen Jenkins and James B. Kelleher; Editing by Greg McCune)
Copyright 2011 Thomson Reuters. Click for Restrictions.