This is the kind of story I saw coming out of Australia 10 years ago. You can't say we had no warning, it's that people in power ignored it. Via the Washington Post:

The city’s hospitals and firefighters this week have been trying to help people who are seared by pavement that can register 160 degrees or hotter. They are treating patients whose temperatures are running as much as 10 degrees above normal by injecting them with frigid IV fluids, blasting them with evaporative cooling fans, and placing them in what look like small inflatable kayaks filled with ice.

Doctors at the burn center this week said they had 10 patients with contact burns serious enough to require hospitalization. The number of burn admissions has grown over the past decade, as temperatures have risen and days with extreme heat have become more common. In 2015, the hospital admitted 43 people during the summer months with burns. Last summer, that number rose to 85, and seven of the people died.

The most common cases, doctors here said, are elderly people who fall or those who are under the influence of fentanyl or other drugs and spend minutes or hours splayed on the pavement. Homeless people are particularly vulnerable.

But other cases involve freakish missteps — people burned by their seat belts or mailboxes. Swimmers attempting to walk across not-so-cool cool decks. The hospital has seen truckers who drive barefoot, step down onto a parking lot surface and end up badly blistered. On the hottest days, patients have been scalded by the water coming out of their garden hoses.

Leaving hoses in the sun results in water that is "practically boiling," one doctor said.