Many U.S. cities will see record overnight temperatures amid another heat wave

Millions of people across the United States are facing a prolonged spell of dangerous heat this week. A sprawling heat dome, which caused record-breaking temperatures in the West over the weekend, is now spreading east. Many U.S. cities are expected to experience record overnight temperatures. Health experts warn that overnight temperatures failing to cool down are even more dangerous than soaring daytime temperatures, increasing the risks associated with this current heat wave across the country.