If physicians want evidence of climate change, they may well find it in their own offices. Patients are presenting with illnesses that once happened only in warmer areas. Chronic conditions are becoming aggravated by more frequent and extended heat waves. Allergy and asthma seasons are getting longer. Spates of injuries are resulting from more intense ice storms and snowstorms.

Scientific evidence shows that the world's climate is changing and that the results have public health consequences. The American Medical Association is working to ensure that physicians and others in health care understand the rise in climate-related illnesses and injuries so they can prepare and respond to them. The Association also is promoting environmentally responsible practices that would reduce waste and energy consumption.

In recent months, the AMA has hosted three state-based CME courses on climate change, most recently in Florida in late February. A fourth is planned later for Illinois. Around the time of the Florida session, the AMA joined with the American Public Health Assn. in a conference call to reporters to bring greater attention to climate change. Florida is an apt setting, because it is particularly sensitive to climate change. Rising air and water temperatures and rising ocean levels since the late 1960s have increased the severity of weather, including hurricanes and droughts, and the production of ground-level ozone.

That means more asthma and respiratory illnesses, more heat stroke and exhaustion, and exacerbation of chronic conditions such as heart disease. Florida's large elderly population makes it even more vulnerable to climate change. In the last two years, the Florida Keys have seen a tropical disease rarely apparent in residents of the United States -- dengue fever.

Maine, another state in which the AMA hosted climate-change CME, is seeing similar trends in terms of climate affecting chronic conditions, although instead of injuries from hurricanes, it's expected to have a rising rate of heart attacks and problems related to extreme snow, ice and cold. Climate change produces weather extremes on both ends of the temperature spectrum. In Maine, that's being seen in a marked increase of Lyme disease. It has risen tenfold in 10 years, particularly in the central and northern parts of the state, which had not seen the disease until recently.

The examples of Florida and Maine show how vector-borne diseases are spreading because of climate change. In Florida, changes in migration patterns and temperatures allow for dengue-infected mosquitoes to circulate. In Maine, warmer and shorter winters mean that deer ticks die off in smaller numbers, which means more will breed and advance farther north.

Treating diseases or conditions new to their location -- and finding the ones that are growing worse -- represent only part of the challenge to physicians presented by climate change. Physicians, like everyone else, can help fight the problem at the source by reducing waste and energy consumption through recycling and improving office energy efficiency. Doctors are often employers as well and can embrace policies that encourage employees to walk, bike or take public transportation to work.

The AMA also encourages physicians to work with their state and local health departments to improve the systems' anticipation and awareness of climate-related health issues. The AMA Center for Public Health Preparedness and Disaster Response, and the Climate and Health Literacy Consortium (of which the AMA is a participant) have tips and resources to help.

Climate change is hardly a physician-only concern. However, doctors may find themselves on the front lines in dealing with its serious and immediate problems. Patients are sicker or developing new conditions as a result of changes in the weather. Greater awareness and understanding of the situation, from a medical perspective, is a proper priority.

www.ama-assn.org/amednews/2011/04/04/edsa0404.htm