Many of the dead were found alone, in homes without air conditioning or fans. Some were elderly one as old as 97. The body of an immigrant farm labourer was found in an Oregon nursery.
As forecasters warned of a record-breaking heat wave in the Pacific Northwest and western Canada last weekend, officials set up cooling centers, distributed water to the homeless and took other steps. Still, hundreds of people are believed to have died from Friday to Tuesday.
An excessive heat warning remained in effect for parts of the interior Northwest and western Canada Thursday.
The death toll in Oregon alone reached 79, the Oregon state medical examiner said Thursday, with most occurring in Multnomah County, which encompasses Portland.