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CDC’s Tracking Network in Action

Construction worker wiping sweaty foreheadHeat can affect your heart and lung health. Stay cool and stay hydrated to protect yourself. Visit the Environmental Public Health Tracking Network to see 70 years of new projected heat data.

CDC's Environmental Public Health Tracking Network (Tracking Network) is a dynamic surveillance system that provides information and data about environmental hazards and the health problems that may be related to them. It presents what we know about where environmental hazards exist, where exposures happen, and how targeted action can protect health, reduce illness, and save lives. The Tracking Network is a unique resource that brings together environmental and health information that cannot be found, or is hard to find, anywhere else.

When temperatures rise in the summer time, extremely hot weather can cause sickness or even death. Extreme heat can also make some types of air pollution worse in the summer, and air pollution can affect your health. The Tracking Network, in collaboration with other CDC programs, provides data and tools that you can use to see how extreme heat may affect your health.

New: 70 Years of Extreme Heat Predictions

In addition to 40 years of historical temperature data, the Tracking Network now has modeled data projecting temperature patterns for the next 70 years. These new data show the estimated number of days and nights of projected extreme heat, available as rolling 30-year averages, through the year 2084. Overall, the data show an increase in the projected number of days and nights of extreme heat over the next seven decades; see an animated map of the data below. These data were originally published as part of the recently released National Climate Assessment. CDC's Climate and Health Program adjusted the numbers to county level data and made them available on the Tracking Network. These data can be used to examine or plan for how future changes in extreme heat might affect human health.

Animated Map: Projected number of future extreme heat days.

Extreme Heat and Your Health

Extreme heat events, or heat waves, are one of the leading causes of weather-related deaths in the United States. Heat stress is heat-related illness caused by your body's inability to cool properly. The body normally cools itself by sweating. But under some conditions, sweating just isn't enough. In such cases, a person's body temperature rises rapidly. Very high body temperatures may damage the brain or other vital organs.

The Tracking Network contains data on heat-related deaths and illnesses from 23 states and provides information to help you protect yourself from heat-related deaths or illnesses. You can use the Tracking Network to see if heat-related deaths and illnesses are rising or declining in your state or county. CDC's extreme heat website offers many tips and guidelines for avoiding heat-related illnesses.

Air Pollution (PM2.5) and Heart Disease

Some types of air pollution can be worse in the summer, especially in large cities. Air pollution can be dangerous for many people including those with other medical conditions like heart disease. Fine particles of air pollution, known as PM2.5, can affect anyone, but some people are more vulnerable to health effects than others. People most likely to experience health effects from PM2.5 are:

  • People with heart or lung diseases (for example, asthma)
  • Older adults
  • Babies and children

If you have heart disease, breathing in particle pollution, including PM2.5, can cause serious problems such as a heart attack. Coronary artery disease (CAD, also known as coronary heart disease or ischemic heart disease) is the most common type of heart disease in the United States. While lifestyle habits such as poor diet, lack of physical activity, and smoking are most commonly associated with CAD, the risk of CAD can also increase from being exposed to PM2.5 over long periods.

The Tracking Network has a tool that estimates the number of CAD-related deaths that could be prevented by reducing PM2.5 levels. Reducing PM2.5 levels by 10% could help prevent more than 9,300 deaths related to CAD in the United States (based on 2009 data). Read more about this tool and the health impacts of PM2.5 on the Tracking Network. More information about air pollution is available on CDC's Outdoor Air Quality website.

Tracking in Action

The Tracking Network is used across the country to help states and cities prepare for summer and periods of extreme heat.

Read more about Tracking in Action to see what is happening in other states.

Coming Soon

Several new enhancements and additions are planned for the Tracking Network this year.

  • New pesticide exposure data from the American Association of Poison Control Centers will be available in late summer.
  • We will release a summary of heat stress hospitalizations surveillance data in the fall. The report will show trends in heat stress illnesses during 2000 – 2010 in states that received Tracking Network grants.
  • A new multiple measures comparison feature coming this winter will allow you to compare data sets through interactive, dynamic maps.
  • The Info-By-Location searching feature is being redesigned to be more user-friendly and to include infographic style data displays.

You can stay informed about these new releases by joining our list-serv.

More Information

More Information

Additional resources for Extreme Heat and Climate Change: 

  • Page last reviewed: July 21, 2014
  • Page last updated: July 30, 2014
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