A brutal heat wave now blankets most of the country. Residents live under oppressive alerts as temperatures soar past triple digits in many states. The capital may tie historic highs this week. New York City turned cooling centers like museums and train hubs into sanctuaries for Fourth of July visitors. Boston now braces for dangerous highs too . Forecasters issued warnings from the Midwest straight through the East Coast.
Doctors caution heat exhaustion and dehydration may turn deadly fast . Cities opened extra rec centers and malls for community comfort. Forecasters see little change until at least early next week .