Una cúpula de calor elevará las temperaturas en gran parte de EE.UU. durante el 4 de julio y pondrá en riesgo a millones.

Dangerous heat is expected across large swaths of the U.S. this week, according to the National Weather Service.

Millions across the central and eastern U.S. could face days of triple-digit heat index values.

Sweltering conditions are expected to last through the weekend