* WHAT...Afternoon temperatures in the triple digits for lower elevations and the high desert, mid to upper 90s for higher terrain. Some mild relief overnight with minimum temperatures in the mid to upper 60s in lower elevations and 50s in the higher terrain.
* WHERE...Portions of south central and southwest Idaho and northeast and southeast Oregon.
* WHEN...From 2 PM MDT /1 PM PDT/ Thursday to 9 PM MDT /8 PM PDT/ Saturday.
* IMPACTS...Hot temperatures may cause heat illnesses.