The Fourth of July holiday is arriving under the most dangerous heat conditions many American cities have seen in years — and public health officials are scrambling to protect millions of people who plan to spend it outdoors.
A powerful heat dome has settled over the eastern United States, pushing temperatures into the upper 90s and low 100s across a corridor stretching from Nashville to Boston. With humidity factored in, heat index values on July 4 are forecast to reach 115°F in Richmond, Virginia; 110°F in Washington D.C.; 107°F in Philadelphia; and 103°F in New York City — the kind of readings that public health officials describe as life-threatening without precautions.
