* WHAT...Dangerously hot conditions possible. Afternoon temperatures 105 to 116. Major Heat Risk. Overexposure can cause heat cramps and heat exhaustion to develop and, without intervention, can lead to heat stroke.
* WHERE...In Arizona, Central La Paz, Gila River Valley, Kofa, and Southeast Yuma County. In California, Joshua Tree NP East and Joshua Tree NP West.
* WHEN...From Thursday morning through Monday evening.
* IMPACTS...Heat related illnesses increase significantly during extreme heat events.