Introduction The kidneys are among the body’s most vital organs. They filter toxins from the blood, regulate fluid and electrolyte balance, and help maintain normal blood pressure. With rising temperatures, especially during summer heatwaves, health risks increase significantly. Excessive fluid loss through sweating can lead to dehydration, which poses a direct threat to kidney function. First: How High Temperatures Affect the Kidneys Exposure to extreme heat accelerates fluid loss through sweating. Without adequate hydration, dehydration occurs, which is the most dangerous factor for kidney health. Key effects include: Reduced blood flow: Dehydration decreases renal blood supply, impairing filtration capacity. Increased toxin concentration: Lack of water raises toxin levels, overburdening the kidneys. Higher risk of kidney stones: Concentrated salts and miner promote stone formation. Acute kidney failure: Severe dehydration can trigger sudden kidney shutdown. Electrolyte imbalance: Disturbances in sodium and potassium affect vital body functions. Second: High-Risk Groups Certain populations are more vulnerable to heat-related kidney complications: Elderly individuals Chronic kidney patients Diabetes and hypertension patients Outdoor workers Children Third: Preventive Measures To safeguard kidney health during hot weather, it is recommended to: Drink sufficient water regularly throughout the day. Avoid direct sun exposure during peak hours. Limit diuretic drinks such as excessive caffeine. Eat hydrating foods like fruits and vegetables. Wear light clothing that is loose and breathable. Seek medical advice if symptoms such as flank pain appear. Conclusion High temperatures pose a direct threat to kidney health, particularly when hydration is insufficient. Early prevention of dehydration and maintaining fluid balance are the first line of defense against kidney complications. Protecting kidney function during extreme heat is essential, especially for vulnerable groups. Prepared by: Ms. Tabarak Ahmed Turki Al-Mustaqbal University The First University in Iraq