A relentless heat wave now stretches across most of the country. Thousands live under heat advisories as thermometers spike past triple digits in many states. Washington, D.C. expects shatter daily benchmarks this week. New York City turned cooling centers like museums and train hubs into relief zones for Fourth of July visitors. The city now braces for dangerous highs too . Forecasters extended warnings from the Midwest down to the East Coast.
Medical professionals advise heat exhaustion and dehydration might turn deadly within hours. Cities opened extra rec centers and malls for community comfort. Experts expect little change until at least early next week .