It's so hot, air conditioners are melting.
Or, more accurately, they are being overtaxed by the heat and humidity that has engulfed much of the nation and caused the National Weather Service in Louisville to issue an excessive heat warning for Kentucky. The warning is in effect until Saturday.
"With 95-degree air and with 70 and 80 percent humidity, that is way outside the design criteria" for older air conditioners, said Bret Melrose, president and owner of Fayette Heating and Air in Lexington.
"These units are laboring intently," he said. "They run 24/7. They're never ever turning off."
That is, until they break.
As the temperature reached 93 degrees on Thursday, with a heat index of about 107, Fayette Heating and Air technicians answered nearly 500 calls for service, Melrose said, compared with 200 calls on an average day with mild temperatures.
Friday's high temperature is expected to be 94 degrees, with a heat index — a combined measurement of heat and relative humidity — of 106. On Saturday, highs will reach 92 with a heat index of 104, University of Kentucky meteorologist Tom Priddy said.
On Thursday, four people in Lexington were taken to the hospital with confirmed "heat illness," fire department Battalion Chief Marshall Griggs said. More people than usual were also taken to the hospital with general sickness and seizures, which might have been related to the heat.
"It's been a busy day for us," Griggs said.
Workers and athletes did what they could to drink enough during the hottest stretch of the day.
At the corner of Main Street and Midland Avenue in Lexington, Danville road worker Jason Caldwell Jr. pushed a "thermo cart," a sort of portable furnace that melts plastic, which is then laid down to create stripes on the road.
Caldwell said he and his team of five contractors drink a five-gallon cooler of water each day. On Thursday, they needed a refill.
The Fifth Third Bank Tennis Championships, a tournament being played at the University of Kentucky, continued despite court temperatures reaching 126 degrees.
Adam Tyson, an athletic trainer for the men's circuit, said trainers make sure players have plenty of water and iced towels, and umbrellas to provide shade.
"A lot of it comes down to the players doing what they can to properly prepare for these conditions," Tyson said, a tricky proposition since some players have flown in from areas of the country that are "75 degrees and overcast right now."
John Bobel, spokesman for Lexington's Division of Emergency Management, said the city would keep open two "relief centers" — buildings where residents without air conditioning are invited to stop in and cool off.
The Dunbar Community Center on North Upper Street and the Lexington Senior Center at the corner of Alumni Drive and Nicholasville Road will open at 8 a.m. Friday. Pools and aquatic centers will give discounted admission through the course of the heat warning.