When Michael Howard arrived for a checkup with his lung specialist, he was worried about how his body would cope with the heat and humidity of a Boston summer.

“I lived in Florida for 14 years, and I moved back because the humidity was just too much,” Howard told pulmonologist Dr. Mary Rice as he settled into an exam room chair at a Beth Israel Deaconess HealthCare clinic.

Howard, 57, has chronic obstructive pulmonary disease (COPD), a progressive lung disease that can be exacerbated by heat and humidity. Even inside a comfortable, climate-controlled room, his oxygen levels worried Rice.

Howard reluctantly agreed to try using portable oxygen, resigned to wearing the clear plastic tubes looped over his ears and inserted into his nostrils. He assured Rice he has an air conditioner and will stay inside on extremely hot days. The doctor and patient agreed that Howard should take his walks in the evenings to be sure he gets enough exercise without overheating.

Then Howard turned to Rice with a question she didn’t encounter in medical school: “Can I ask you: Last summer, why was it so hot?”

Rice, who studies air pollution, was ready.

“The overall trend of the hotter summers that we’re seeing [is] due to climate change,” Rice said.

For Rice, connecting climate-change consequences — heat waves, more pollen, longer allergy seasons — to her patients’ health is becoming routine. She is among a small but growing number of doctors and nurses who discuss those connections with patients.

In June, the American Medical Association, American Academy of Pediatrics and American Heart Association were among a long list of medical and public health groups that issued a call to action asking the U.S. government, business, and leaders to recognize climate change as a health emergency.

The World Health Organization calls climate change “the greatest health challenge of the 21st century,” and a dozen U.S. medical societies urge action to limit global warming.

Some medical societies provide patients with information that explains the related health risks. But none have guidelines on how providers should talk to patients about climate change.

There is no concrete list of “do’s” — as in wear a seat belt, use sunscreen and get exercise — or “don’ts” — as in don’t smoke, don’t drink too much and don’t text while driving ― that doctors can talk about with patients.

Climate change is different, said Rice, because an individual patient can’t prevent it. So Rice focuses on steps her patients can take to cope with the consequences of heatwaves, such as more potent pollen and a longer allergy season.

That was Mary Heafy’s main complaint. The 64-year-old has asthma that is worse during the allergy season. During her appointment with Rice, Heafy wanted to know why her eyes and nose were running and her chest feels tight for longer periods every year.

“It feels like once [the allergy season] starts in the springtime, it doesn’t end until there’s a killing frost,” Heafy told Rice.

“Yes,” Rice nodded, “because of global warming, the plants are flowering earlier in the spring. After hot summers, the trees are releasing more pollen the following season.”

So Heafy may need stronger medicines and more air filters, her doctor said, and may spend more days wearing a mask — although the effort of breathing through a mask is hard on her lungs as well.

As she and the doctor finalized a prescription plan, Heafy observed that “physicians talk about things like smoking, but I don’t know that every physician talks about the environmental impact.”

Why do so few doctors talk about the impact of the environment on health? Besides a lack of guidelines, doctors say, they don’t have time during a 15- to 20-minute visit to broach something as complicated as climate change.

And the topic can be controversial: While a recent Pew Research Center poll found that 59% of Americans think climate change affects their local community “a great deal or some,” only 31% say it affects them personally, and views vary widely by political party.

We contacted energy-industry trade groups to ask what role — if any — medical providers should have in the climate change conversation, but neither the American Petroleum Institute nor the American Fuel & Petrochemical Manufacturers returned calls or email requests for comment.

Some doctors say they worry about challenging a patient’s beliefs on the sometimes fraught topic, according to Dr. Nitin Damle, a past president of the American College of Physicians.

“It’s a difficult conversation to have,” said Damle, who practices internal medicine in Wakefield, R.I.

Damle said he “takes the temperature” of patients, with some general questions about the environment or the weather, before deciding if he’ll suggest that climate change is affecting their health.

Dr. Gaurab Basu, a primary care physician at Cambridge Health Alliance, said he’s ready if patients want to talk about climate change, but he doesn’t bring it up. He first must make sure patients feel safe in the exam room, he said, and raising a controversial political issue might erode that feeling.

“I have to be honest about the science and the threat that is there, and it is quite alarming,” Basu said.

So alarming, Basu said, that he often refers patients to counseling. Psychiatrists concerned about the effects of climate change on mental health say there are no standards of care in their profession yet, but some common responses are emerging.

One environmental group isn’t waiting for doctors and nurses to figure out how to talk to patients about climate change.

Molly Rauch, the public health policy director with Moms Clean Air Force, a project of the Environmental Defense Fund, urges the group’s more than 1 million members to ask doctors and nurses for guidance. For example: When should parents keep children indoors because the outdoor air is too dirty?

“This isn’t too scary for us to hear about,” Rauch said. “We are hungry for information about this. We want to know.”

Martha Bebinger is a correspondent, Kaiser Health News.

Image credit: Shutterstock.com