The loss of sleep due to rising nighttime temperatures poses significant health risks, including reduced cognitive performance, mood disturbances, and weakened cardiovascular and immune systems. Vulnerable groups, such as older adults and those in lower-income regions, face heightened risks due to limited access to cooling solutions like air conditioning. Regions with already high nighttime temperatures, including parts of the Middle East, South Asia, and West Africa, are particularly affected. In the U.S., cities in states like Arizona, California, and Florida reported the highest climate change-linked sleep losses, averaging seven to nine hours annually.