I talk a lot about parts of the world becoming uninhabitable, as the temperature rises, but I generally focus on stuff like the increase in wet bulb conditions. Beau of the Fifth Column has rightly pointed out that there’s another way in which heat makes the outdoors dangerous – the temperature of pavement. As you’re probably aware, when temperatures climb past the 90s, asphalt in the sun can get literally hot enough to fry eggs. Those conditions are increasing as well, meaning that for longer periods of the year, simply falling over can give you severe, even life-threatening burns. This is a good reason to be careful during heatwaves (be careful of your dogs as well – their paws cook just as easily as our skin), but it’s also a good reason not to keep expanding roads and car-dependence. Paving the world is increasingly going to turn places like parking lots into death traps. Content warning for descriptions of burns:

“Summers are our busy season, so we anticipate that this sort of thing is going to happen. But this is really unusual — the number of patients that we’re seeing and the severity of injuries — the acuity of injuries is much higher,” said Dr. Kevin Foster, director of burn services at the Arizona Burn Center at Valleywise Health. “The numbers are higher and the seriousness of injuries are higher, and we don’t have a good explanation for it.”

Every single one of the 45 beds in the burn center is full, he said, and one-third of patients are people who fell and burned themselves on the ground. There are also burn patients in the ICU, and about half of those patients are people burned after falls.

“It has definitely taken its toll,” Foster said.

The area has been hotter than usual, even for Arizona, and that, experts said, means that the ground can be dangerous for anyone whose bare skin comes into contact with it.

Asphalt is dark and dense. While concrete is lighter and reflects some sunlight, when the sun shines on asphalt, its dark color causes it to absorb light and it heats up.

Since it is a dense material, it also holds the heat even after the sun has been shining on it.

On a hot day, asphalt can easily be 40 to 60 degrees hotter than the air, some studies show. Last Thursday, the air temperature reached 119 degrees Fahrenheit. Phoenix had six consecutive days at or above 115 degrees by Saturday; the streak ended Sunday, with high temperatures reaching only 114 degrees.

“The temperature of asphalt and pavement and concrete and sidewalks in Arizona on a warm sunny day or summer afternoon is 180 degrees sometimes. I mean, it’s just a little below boiling, so it’s really something,” Foster said.

It can take only a “fraction of a second” to get a “pretty deep burn,” he said. For people who have been on the pavement for 10 to 20 minutes, “the skin is completely destroyed” and the damage often goes down deep, meaning it is a third-degree burn.

Foster sees burns like that after people survive a house fire. “These are really serious injuries,” he said.

Patients with third-degree burns will require multiple surgeries and have to spend weeks or even months in the hospital and have years of reconstructive surgery and therapy. “It is a really substantial injury,” Foster said.

Be careful out there!