Record high temperatures are a feature of the summer of 2024. While some people are more vulnerable to problems from heat, extreme temperatures can affect all of us. A study in the American Heart Association journal Circulation notes heat and dehydration cause the heart to work harder, putting it under significant stress. Preliminary research found even short-term exposure to high temperatures may increase inflammation and interfere with normal body functions, especially in those with existing heart disease. This could be dangerous and even deadly. Authors advise all of us to avoid extreme outdoor heat of the day—between noon and three—stay well-hydrated with water, not caffeinated or alcoholic beverages.