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. Scientific information used in this document is derived from peer-reviewed synthesis and assessment products, including those published by the United States Global Change Research Program and the Intergovernmental Panel on Climate Change, as well as other peer-reviewed sources and federal agency resources.