Heat dome set to break over 90 U.S. temperature records this week

The National Weather Service warned that more than 90 temperature records could be tied or broken across the United States by Wednesday, most of them for overnight highs. Forecasts show nighttime temperatures remaining at or above 80°F (27°C) in several Florida cities, Galveston, Texas, and Charleston, South Carolina, while locations in the Midwest and Northeast such as Fargo, North Dakota, International Falls, Minnesota, and Portland, Maine are expected to stay above 70°F (21°C).

Health officials emphasized that sustained heat at night poses a greater risk because the body cannot cool down between days. > "That’s where the health outcomes are amplified, particularly for the elderly and vulnerable communities," said Marshall Shepherd, a meteorology professor at the University of Georgia. > "Mortality starts the second or third day" because the body’s inability to cool, added Kristie Ebi, a public health and climate scientist at the University of Washington.

Experts advised residents to watch for early signs of heat stress, such as heavy sweating, muscle cramps and headaches, and to take preventive actions like using air-conditioned spaces, applying cool water, or seeking public cooling centers such as libraries or malls. They also urged people to check on older adults, pregnant individuals and those with pre-existing health conditions.

The heat wave follows a period of extreme temperatures that have already caused heat-related deaths in New Jersey and contributed to wildfires in the western United States.