JACKSON, Miss. -- This heat wave isn't just stifling -- it's deadly.
Extreme temperatures continued Thursday across a large swath of the country, killing more than a dozen people, at least two police dogs and likely contributing to the death of Franklin the rhinoceros at a Mississippi zoo. Arkansas fire departments were volunteering to hose down overheated cattle, and people as far north as Maine were looking for ways to stay cool.
High school football teams and marching bands either practiced indoors or canceled altogether. Tennessee election officials touted air-conditioned polling places as a way to bring in voters, and many cities set up cooling centers for those who needed a break from the sun.
Residents were encouraged to check on their neighbors, especially the elderly.
The scorching temperatures and high humidity made it feel like at least 100 degrees in many places, with heat advisories in effect for 18 states.
''This heat wears on everybody,'' said Sandy Shamburger, who runs Rankin Sod Farm in Brandon, Miss. ''We rigged up lights on a sod harvester so we can work at night.''
Still, not even nightfall brings much relief, with temperatures lingering in the 80s in some places.
The heat has been blamed for at least 13 deaths in Mississippi and Tennessee alone, including a man who had a heart attack while mowing his lawn and a construction worker who was spreading concrete. Maryland authorities on Thursday reported two heat-related deaths from early last week.
Two concrete sections of a U.S. highway in central Mississippi buckled Tuesday, when temperatures hit 103 degrees.
''I can assure you, it was probably 120 degrees on the concrete,'' said Steve Grantham, assistant district engineer for the Mississippi Department of Transportation.
Animals also have fallen victim. Authorities also said a police dog died Wednesday from heat exhaustion in Tennessee's Blount County after a search for two burglars. A deputy and another dog, also from the Blount County Sheriff's Office, were treated for heat exhaustion. A Fayette County, Ga., handler had also reported his K-9 died because of the heat, said Blount County Sheriff's Department spokeswoman Marian O'Briant.
Heat may have also been to blame for the death of a 37-year-old rhinoceros named Franklin at the Jackson Zoo in Mississippi, where temperatures have surpassed 100 degrees in recent days.
And seven puppies died Wednesday while in the cargo hold of an American Airlines jet in Tulsa, Okla., said airline spokeswoman Mary Frances Fagan.
The heat wave has stretched far beyond the Deep South, where people are more accustomed to long, steamy summers. In the nation's capital, temperatures have hit at least 90 degrees on 45 days so far, said National Weather Service meteorologist Heath Sheffield. There were only 22 such days last year.