Overview

• Extreme heat warnings cover major cities from Philadelphia to Boston as highs approach or exceed 100°F on Monday and Tuesday.
• More than 170 million Americans across the country will be impacted by the first significant heat wave of the season.
• Little to no overnight relief is expected, with lows holding above 80°F and increasing the chance of heat-related illnesses.
• Municipalities have activated emergency heat plans and opened dozens of cooling centers, including 40 in Philadelphia and 248 in New York City.
• The National Weather Service warns that unacclimated bodies, especially among the elderly and children, face elevated danger during this prolonged heat event.