The combination of extreme heat and elevated humidity levels poses a significant risk of heat-related illnesses, particularly for vulnerable populations such as the elderly and those with pre-existing health conditions. The oppressive conditions may also strain energy systems due to increased air conditioning use. Severe thunderstorms are expected in the Plains and Midwest early in the week, potentially causing localized damage. The East Coast will see relief from the heat by Thursday, but the Southeast will remain at risk for heat stress and fire hazards due to dry conditions.