Key keywords: extreme heat Midwest 2024, East Coast sticky humid weather, US national heat advisory, dangerous heat index, heat-related illness prevention, US power grid pressure, agricultural heat stress, climate change extreme weather The National Weather Service (NWS) issued widespread heat advisories and excessive heat warnings across 28 U.S. states on Tuesday, as a record-breaking heat dome that has baked the East Coast for 10 consecutive days expands westward into the Midwest. For the East Coast, the sweltering, muggy conditions show no sign of easing through the end of the week. Major metropolitan areas including New York City, Philadelphia, Boston, and Washington D.C. are reporting heat index values between 105°F and 112°F during peak afternoon hours, with overnight lows only dropping to the mid-70s°F, offering no relief for residents without access to air conditioning. Local governments have activated more than 400 cooling centers across the region, extended public pool hours, and deployed outreach teams to check on unhoused populations, elderly residents, and low-income households that may be unable to afford cooling costs. Utility providers are also urging customers to reduce non-essential electricity use between 2 p.m. and 7 p.m. to avoid rolling blackouts, as power grids are operating at 92% of maximum capacity across the Northeast. Meanwhile, the sudden arrival of extreme heat in the Midwest has caught many communities off guard. States including Ohio, Indiana, Illinois, Iowa, and Missouri are facing their first major heat event of the summer, with temperatures climbing 20 to 25 degrees above the seasonal average. In Chicago, public school districts adjusted outdoor recess and sports schedules on Tuesday to avoid exposing students to dangerous heat, while agricultural officials warned that sustained high temperatures and below-average rainfall could threaten corn and soybean yields across the Corn Belt, which is responsible for nearly 80% of U.S. grain production. The NWS noted that the heat dome is expected to remain in place across most of the central and eastern U.S. until at least next Monday, with some areas in southern Illinois and western Kentucky likely to break 100-year high temperature records by the weekend. Public health officials have emphasized the importance of staying hydrated, avoiding prolonged outdoor activity during peak heat hours, and checking on vulnerable neighbors to reduce the risk of heat stroke and other heat-related illnesses, which have already caused 17 confirmed hospitalizations across the affected regions so far this week.