Extreme heat events in the United States are already occurring and expected to become more common, more severe, and longer-lasting as our climate changes. The U.S. Environmental Protection Agency (EPA) and the CDC developed this booklet to identify steps that you can take now to prepare for an extreme heat event--and to help your families, friends, and neighbors, too. This booklet answers some of the key questions about extreme heat in a changing climate: why extreme heat is on the rise, how it might affect you, and what you can do before and during an extreme heat event to reduce your health risk. Contents include: What is Extreme Heat? Why is Extreme Heat on the Rise? What Might I Experience in the Future? How Can Extreme Heat Affect Me? How Common Are Heat-Related Illnesses and Deaths? Who is Most at Risk from Extreme Heat? What is the Urban Heat Island Effect? What Should I Do During an Extreme Heat Event? What Can I Do to Reduce My Risk Before an Extreme Heat Event?