The American Heart Association (AHA) advises taking measures to protect yourself from the record-breaking heat engulfing much of the United States this week. This is especially true for the elderly and people with high blood pressure, obesity or a history of heart disease or stroke. When you are hot and dehydrated, your heart pumps more blood and reroutes it to your skin in an effort to cool itself. As a result of extreme temperatures reaching an average daily temperature of 109 degrees Fahrenheit (as it has this week in the Southwest), the number of heart disease deaths may double or triple, and the more extreme the temperatures, the greater the risk of strokes.