This story was produced by Grist and co-published with Arizona Luminaria. This story is part of the Grist series Vital Signs, exploring the ways climate change affects your health. This reporting initiative is made possible thanks to support from the Wellcome Trust.

John Galgiani has been waiting for this call.

The 79-year-old physician is sitting on a chair in a side office at a health clinic in Phoenix, Arizona, long legs crammed under the table in front of him, hands folded at his stomach, when his cell phone rings. “There’s my guy,” he says.

The man on the other end, a physician who works in Tucson, is a touch less relaxed. One of his patients has been in and out of the hospital with a respiratory infection so severe that at one point she coughed up blood. Her skin is flaking, she’s losing her hair, and now the ventricles in her heart are taking too long to refill with blood between beats. The physician suspects some of these symptoms are being caused not by her underlying condition, but by the medication he has her on. The problem is, her insurance is refusing to cover a more expensive alternative.

Galgiani, the country’s leading expert on the disease they’re talking about, quickly cuts him off. Take the patient off the medication, he says, and see how she does. If she improves, show the insurance company proof and force its hand. “That’s actually a good idea,” the doctor replies.