Skin and gastrointestinal infections are on the rise in Houston, Texas as the result of sewage-laden floodwaters. In Puerto Rico, the thousands of people living without clean water are at an increased risk of all sorts of diseases. Natural disasters are public health disasters.

As temperatures go up due to climate change, extreme weather events (like Hurricane Maria and Hurricane Harvey) become more frequent, and more intense. Warmer temperatures are also a public health problem in and of themselves, aiding the spread of infectious diseases and increasing rates of malnutrition. The changing climate is going to make people sick.

And the healthcare system in the United Sates—which is supposed to keep people healthy—is partially to blame.

Between powering facilities, manufacturing medical supplies, creating pharmaceuticals, and other activities, the U.S. healthcare system is responsible for a solid chunk of the greenhouse gas emissions that contribute to climate change; it released the equivalent of 614 million metric tons of carbon dioxide in 2013, and around 10 percent of the total emissions in the United States.

However, most healthcare professionals don't have a good understanding of the harms caused by their industry, says Jodi Sherman, professor of anesthesiology and director of sustainability for the department of anesthesiology at Yale University. "The harms are indirect," she says. "We're concerned with the patients right in front of us. It's hard for us to wrap our mind around how we're affecting human health that's distant geographically, and also in time."

As citizens, Sherman says, everyone has a responsibility to try and reduce their climate impacts. But for the healthcare system, there's an additional charge: "We're the only ones that have the principle of 'first, do no harm."