Last week, extremist radio host Rush Limbaugh mocked the heat wave spreading across the country, arguing that the heat index was a goverment concoction to make people afraid of global warming. The heat index, which combines temperature and humidity readings to provide an estimate of what the equivalent temperature would feel like without humidity, is used by meteorologists and public health officials to determine the threat posed by heat waves.
In an exclusive interview with ThinkProgress, one of the top public health experts in the nation’s greatest metropolis, New York City, explained that the heat index and heat waves are no laughing matter. Dr. Thomas Matte, professor of urban public health at the CUNY School of Public Health, has investigated the dangers of heat waves to the 8 million residents of New York City, and is the co-author of the paper, “Summer heat and mortality in New York City: how hot is too hot?”
Matte emphasized that the heat index is a useful tool that combines two of the most important factors behind heat stress, a potentially deadly syndrome, particularly for the sick, young, and elderly:
There’s many many studies that have been done how people respond to hot conditions. They have shown that there are more variables than just ambient temperature. The environmental variables include obvious things like shade. Also, because humans cool themselves by sweating, when the humidity is higher the evaporation is less efficient.
On a warm day, a dry day will feel more comfortable than a humid day.
Heat stress isn’t just a matter of comfort, especially for people with a heart condition, or emphysema. A normal healthy person can tolerate a lot of that stress. Under some conditions it can be just discomfort, but under other conditions it can be life threatening.
“The reason that heat index is used is because high humidity makes it feel hotter, and causes more heat stress,” Matte said. Debunking Limbaugh’s claim that the heat index is a recent government plot, Matte noted, “it’s been done that way for a long long time.”
The weekend’s heat wave was the type that kills, Matte said:
When the temperature gets into this range, more people die of chronic health problems and deaths occur from heat stroke. Anybody who has a health condition or is elderly is at risk. These heat waves do kill people. Of all natural disasters, they kill more people than any other. This is not a hypothetical risk. People really die from heat waves.
When asked if he uses the heat index to promote concerns about global warming, Matte scoffed. “This is not really a climate change issue,” he responded. “When we warn people to take precautions, and we use the heat index to do that, climate change is not what’s on my mind.”
A 94-year-old Brooklyn woman has been confirmed to have been killed by the heat wave.