A tightening heat dome over the central and western United States will drive dangerous temperatures through Monday, exposing a substantial share of the population to high heat.
The strongest dome is taking shape over the Rockies and Plains, while heat advisories continue for portions of southern Colorado and several Midwestern states.
Thunderstorms may fire up in scattered areas but will provide minimal relief from the oppressive heat.
Forecasters warn the dome's intensity will slow cool fronts and carry record-breaking conditions deep into next week.
Residents are urged to stay hydrated, limit outdoor effort during peak hours, and keep an eye on older relatives as the stretch of searing heat intensifies the length of the country's interior.