Weather events such as heat waves, hurricanes, tornadoes, drought, flooding, etc., can have both direct and indirect effects on human health and the environment. Scientists look at historical weather patterns related to temperature, precipitation, wind, etc., as well as use predictive models to study the dynamics of the weather and climate to forecast future patterns.
There is an important difference between "weather" and "climate." "Weather" is what is happening in a specific place in the atmosphere on a given day. "Climate" is looking at weather patterns over a period of time. A saying among meteorologists is that "climate is what you expect, weather is what you get."
Whether or not human activities are influencing climate is a matter of global debate. However, scientific data shows that the Earth's climate is changing and is currently in a warming trend. According to the National Aeronautics and Space Administration (NASA), the average global temperature has increased about 1.4º Fahrenheit (0.8º Celsius) since 1880.
The focus of this page is on the health effects associated with heat. Additional types of weather-related health outcome data may be added at a future date.
Heat can impact people in different ways depending on several factors including the vulnerability of exposed populations. For example, a person's age and pre-existing health conditions such as heart disease and diabetes may increase the risk of suffering from heat-related health illnesses. Certain medications may result in dehydration thus making individuals more susceptible to suffering from a heat-related illness.
Socio-economic factors, such as the ability to afford air conditioning or adequate insulation, can also impact vulnerability and may leave some residents at risk of exposure to extreme temperatures. Individuals with limited resources are more likely to live in substandard housing which may expose them to higher levels of environmental hazards. They may also have limited access to health care to help maintain good health and may not have the ability to receive medical attention when needed.
Heat can also have a direct or indirect impact on human health. For example, heat may have a direct effect of causing a heat related rash or even a life threatening heat stroke; or an indirect effect such as causing a heat wave that increases the demand for electricity which uses more fossil fuels. This additional fossil fuel usage can generate more airborne particulates into the environment and result in negative health effects associated with breathing the additional pollution. Heat may also affect the environment by increasing ground-level ozone concentrations which in turn may cause lung damage and increase the severity of asthma attacks and other respiratory diseases.
The CDC has selected three indicators that result from extreme heat events to be tracked by the Environmental Public Health Tracking program. Data is reported when heat is either the main cause or a contributing factor for the following three reportable measures. The focus of this page is to display data and information.
By looking at these indicators over time, we hope to gain a better understanding of the possible health effects and risks from exposure to heat as it relates to specific groups of people. This will also aid us in developing awareness and educational tools to help better inform vulnerable communities.
1. Know the environmental and personal risk factors.
A. Environmental risk factors include:
- High temperature and/or humidity (heat index)
- Direct exposure to the heat sources
- Limited air movement
- Type and duration of physical exertion
B. Personal risk factors include:
- Age, weight, and physical condition – People who are older or overweight are more susceptible to heat related illness or injury than someone in good physical condition.
- Acclimation to working in the heat – Someone who has adjusted to being in or working in higher temperatures and changes in weather conditions is less likely to be negatively impacted by the heat than someone who is not.
- The amount of water, alcohol, and caffeine that has been consumed – Drinking water keeps your body hydrated, whereas alcohol and/or caffeine increases water loss and could lead to dehydration.
- Use of certain types of medications - Some medications such as diuretics (often used to treat high blood pressure, edema, glaucoma) increase excretion of water from the body which can lead to dehydration.
2. Know the forecast and plan accordingly:
- Wear light and/or loose fitting clothing
- Drink plenty of fluids such as water or sports drinks
- Take frequent breaks in the shade
- Wear protective clothing, a hat, and sunscreen
Age Adjusted Rate**
|Crude Rate* per 100,000 population based on current year Census estimates.
Age Adjusted Rate** per 100,000 population based on current year
Census estimates (Adjusted to 2000 standard population).
County rates suppressed due to low counts.