Extreme heat - an "unseen threat" – burns U.S. urban poor
When scorching heat descends on New York City in the summer, Harlem resident Evelyn Jenkins-Smith finds breathing difficult when she goes outside.
“My chest feels heavy,” said the retiree, who suffered a minor stroke two years ago.
So the 73-year-old widow cloisters herself in her sweltering apartment, which lacks air conditioning.
Jenkins-Smith is among the growing number of city dwellers whose health is at risk from increasingly hotter summers - a threat that has prompted cities nationwide to look for innovative ways to keep their most vulnerable residents safe and cool.
Rife with asphalt and concrete that absorb and radiate heat, many U.S. cities amount to giant heat traps, scientists say.
The phenomenon is known as the urban heat island effect. It can add as much as 5 degrees Fahrenheit (3 degrees Celsius) to daytime temperatures in cities, according to the U.S. Environmental Protection Agency.
The problem is even worse at night, when city temperatures can be as much as a whopping 22 degrees Fahrenheit (12 degrees Celsius) warmer than green rural areas, where heat is more effectively released back into the atmosphere, the agency said.
Countrywide, heat is the number one cause of death from extreme weather events - including threats such as floods and hurricanes, according to the National Weather Service. Its data show that high temperatures killed an average of 131 people a year in the United States between 1987 and 2016.
When the heat index - a measure that combines temperature and humidity - climbs above 95 degrees Fahrenheit (35 degrees Celsius), it becomes harder to sweat off heat, leaving older adults, in particular, at risk of suffering heat stroke.
High temperatures also can aggravate pre-existing health issues, such as heart conditions, according to the U.S. Centers for Disease Control and Prevention.