OKLAHOMA CITY — The heat was on Monday for millions of Americans from the Upper Midwest to Texas and Oklahoma, where roads buckled and poultry farmers deployed fans and watered rooftops to protect flocks.
The National Weather Service put 18 states stretching from North Dakota to Texas and East to Ohio under a heat warning, watch or advisory. It said as many 13 deaths in the past week in the Midwest could be blamed on the effects of the heat.
When humidity was factored in, the heat index made it feel as hot as 110 degrees in a broad swath of the nation.
"This is unusual," said Pat Slattery, spokesman for the Weather Service. "There's no sugar-coating anything here."
In steamy Oklahoma City, 13 state government buildings at the capitol were closed after a break in a water main that shut off air-conditioning systems.
Computer systems in Oklahoma's state agencies were turned off and 1,000 employees sent home, said spokeswoman Sara Cowden of the Department of Central Services.
"We're shutting everything down that generates heat," she said.
In Oklahoma City, which saw a 28th day of triple-digit heat, two lanes of a major interstate in downtown were closed Monday morning after buckling on a bridge caused steel expansion joints to rise, damaging cars as they passed over.
The city is on pace to break its record for days at 100 or above — 50 set in 1980 — with triple-digit heat possible through September.
In Tulsa, a hole opened in the pavement of a highway bridge and a section of U.S. 75 in a nearby town buckled.
It's even worse in western Oklahoma, where temperatures at 110 or above have been common in recent weeks. In Enid, asphalt at a major intersection along U.S. Highway 412 buckled Saturday night from the intense heat.
Last week, a buckled road near Enid caused a motorcyclist to go airborne and then tumble for hundreds of feet. The driver, who was wearing kevlar-laced gear, was airlifted to a hospital where he was being treated for injuries that included broken bones and an injured back.
Oklahoma poultry producers have deployed fans and some even hose down rooftops to try to lower temperatures, John Ward, executive vice president of the state Poultry Federation told msnbc.com.
"We haven't lost a lot of birds," at least so far, he said, adding that "we probably lost more chickens to snow storms" that caved in roofs in recent winters.
The U.S. Humane Society worries that even brief power outages can kill thousands of chickens, as was the case in North Carolina last week.
"The vast majority of farm animals are confined indoors at all times, meaning if there’s a power outage, you can have tens of thousands of animals in one building dead within an hour, said Paul Shapiro, who tracks farm animal conditions for the activist group.
"The problem is inherent to large operations," he added. Steps like shaded, outdoor access "can help avert" heat deaths, he said.
'Most significant' heat wave in 5 years likely
The heat wave is set to press on this week across the central U.S., with high humidity adding to the misery.
"This will likely be the most significant heat wave the region has experienced in at least the last five years," the National Weather Service said.
Heat indexes are predicted to stay in the triple digits, and the oppressive temperatures are likely to spread to the East Coast later in the week.
At the other end of the U.S., the Seattle area has had what a local TV station is calling "the 78-minute summer." KOMO TV reported Monday that that's the amount of time it has been 80 degrees or warmer so far this summer.
Temperatures in places such as Dodge City, Kan., and Woodward, Okla., were forecast to be above 100 degrees through Saturday. Wichita, Kan., will see temperatures higher than 100 degrees through Sunday.
This heat wave is particularly dangerous because many of the areas under its umbrella are not used to prolonged high temperatures and humidity, according to the weather service. Plus the overnight temperatures are not expected to dip low enough to provide any reprieve.
"The cumulative effects, when it doesn't cool down overnight, you get no relief," Slattery said.According to the weather service outlook, the central U.S. from North Dakota to Texas and east to the Carolinas, excluding parts of the Northeast and Southern Florida, will see excessive heat.....www.msnbc.msn.com