Urban Heat Islands Expose Millions To Dangerous Heat, With Poor And Minorities Most At Risk

Urban heat island effect causes temperatures to spike 8°F or more in cities.
Analysis of 44 major US cities found over 40 million people live in these hot zones.
New York, Chicago, San Francisco and Miami see some of the biggest urban heat spikes.
Increased tree cover, reflective rooftops and other measures can help reduce the effect.
Long history of discrimination leaves low-income and minority communities most vulnerable to extreme heat.