* WHAT...Dangerously hot late-season conditions expected with high temperatures up to 112 to 116 in Death Valley and the Colorado River Valley; up to 105 to 110 in the Las Vegas Valley, Moapa Valley, and Pahrump Valley.
* WHERE...Portions of northwest Arizona, southeast California, and southern Nevada.
* WHEN...From 10 AM PDT /10 AM MST/ to 8 PM PDT /8 PM MST/ Thursday.
* IMPACTS...Heat-related illnesses increase significantly during extreme heat.