Triple-digit heat suspected in 4 deaths in Oregon: "Don't consider yourself invincible"

Triple-digit heat was being investigated Thursday as the cause of death for four people in Oregon as a sweltering heat wave enveloped the Pacific Northwest — and the forecast showed no sign of letting up soon in a region unaccustomed to such temperatures.

The Oregon State Medical Examiner's Office said at least three people have died from suspected hyperthermia during the heat wave in Multnomah County, which is home to Portland. A fourth death was suspected due to heat in Umatilla County in the eastern part of the state, the state agency told KGW-TV.

The deaths occurred on Monday, Wednesday and Thursday. The state medical examiner's office said the heat-related death designation is preliminary and could change after further investigation.