The heart is one of the organs most affected by high temperatures, as hot weather places additional stress on the cardiovascular system to maintain the body’s normal temperature. With the increasing frequency of heat waves during the summer, raising awareness about the associated health risks has become more important, particularly for older adults and individuals with cardiovascular diseases. When the body is exposed to high temperatures, it cools itself by dilating blood vessels and increasing sweat production. This process can lead to significant loss of fluids and electrolytes if they are not adequately replaced. As a result, the heart must pump more blood to deliver oxygen to body tissues and regulate body temperature, placing extra strain on the cardiovascular system. Dehydration caused by excessive fluid loss may also lead to low blood pressure, dizziness, and fatigue. In addition, an imbalance of electrolytes, such as sodium and potassium, can contribute to irregular heart rhythms, especially in people with pre-existing heart conditions. Individuals with heart failure, hypertension, or coronary artery disease, as well as older adults, are particularly vulnerable to the effects of extreme heat. Furthermore, certain medications, including diuretics and antihypertensive drugs, may reduce the body’s ability to adapt to high temperatures. Therefore, patients should always follow their physician’s advice and avoid changing their medications without medical consultation. To reduce the impact of hot weather on heart health, it is recommended to drink adequate amounts of water unless otherwise advised by a healthcare provider, avoid direct sun exposure during peak daytime hours, wear lightweight and light-colored clothing, engage in physical activity during the early morning or evening, and maintain a balanced diet rich in fruits and vegetables to support proper hydration and electrolyte balance. Prevention remains the most effective strategy for minimizing heat-related cardiovascular complications. Following healthy lifestyle practices and maintaining regular medical follow-up, particularly for individuals with heart disease, can significantly reduce health risks and help preserve cardiovascular health throughout the summer season. Al-Mustaqbal University The First University in Iraq