The persistent heat poses significant health risks, particularly to vulnerable populations such as the elderly, pregnant individuals, and those with pre-existing health conditions. High overnight temperatures can lead to heatstroke, cardiovascular strain, and other heat-related illnesses, as the body is unable to cool down adequately. Health experts warn that the effects of sustained heat exposure may not be immediately apparent, with severe health outcomes often manifesting after two or three days. Communities in the Midwest, Northeast, and southern U.S. are at heightened risk due to the unusual nature of these conditions in some regions (AP News, 2026-07-13).