In a swath that stretches across the Pacific Northwest, 13 million people are sweltering under an extreme heat wave that has shattered records in Portland and Seattle, boosting temperatures in both cities well above 100 degrees Fahrenheit over the weekend and into this week. 

A “heat dome” trapping the heat wave over the region has sent many without home air conditioning to emergency shelters to keep safe from the intense heat, which can be deadly. The heat is expected to persist into mid-week.

Washington state's King County, which includes Seattle, recently released a heat map showing less affluent neighborhoods, where tree cover is low, experience the dangerous effects of heat more acutely than their more affluent counterparts. As