The heat dome will affect more than two dozen states, with urban areas facing the highest risks due to heat retention in buildings and pavement. Prolonged exposure to high temperatures and humidity increases the risk of heat-related illnesses, such as heat exhaustion and heatstroke. Cities like Chicago, St. Louis, and Kansas City will see consecutive days of extreme heat, while Eastern cities like Philadelphia, Washington, D.C., and New York could experience heat indices exceeding 110°F (43.3°C). In the Southwest, wildfire conditions remain critical, with strong winds and dry air worsening fire behavior and air quality.