The United States is in a record heat wave, with tens of millions of people on alert. A dome of persistent heat covers a large part of the Midwest and extending into the northeast. The phenomenon traps hot air and humidity and worsens the temperature “resembles” much higher than it really is.
Health experts and climatologists have described the effects of extreme heat on the human body, that the populations are most at risk and the means to mitigate it.
What is thermal stress and what are the causes?
It occurs when the body undergoes an accumulation of heat, at a level more than it can release. “The human body has this fantastic ability to cool by the evaporation of sweat,” said Uwe Reischl, professor at the School of Public and Population Health at the Wood State University. But even when the body produces sweat, evaporation can be limited due to humidity in the air.
Another factor that causes an increase in body temperature is when a person wears clothes that prevent transmission from free from skin. And when the body does not have enough water, it becomes dehydrated to the point that it is no longer able to produce sweat.
How is it connected to the current heat dome phenomenon?
Hot air is able to maintain more humidity than cold air. “Thus, the higher the heat dome, the higher the humidity levels,” said Reischl. Urban environments with many buildings, paved roads and car parks exacerbate the probability of thermal stress, because they absorb heat from the sun (and release it) throughout the day.
What are the signs of thermal stress?
“Thermal stress is a spectrum,” said Kristie Ebi, environmental and professional health teacher at Washington University. Symptoms can go from small reddish blisters on the hands to fainting. In extreme cases, if the body temperature exceeds 103F (39C), it can cause a heat stroke, which can cause the brain swelling and other internal organs and can be fatal.
Most Assigned by thermal stress?
Children, the elderly and the speakers are among the most vulnerable to thermal stress. “Athletes and outdoor workers can be much more at risk of thermal stress,” said EBI, because the more people move or work, the more their body must get rid of heat. These circumstances are heavier for people like agricultural workers, who must be protected from physical or chemical dangers, such as pesticides. They must wear protective clothes, which can interfere with their bodies’ ability to evaporate sweat.
How do human bodies recover from thermal stress?
“When we are exposed to high temperatures, we need time for our body to cool down, and the night is normally when this happens,” said EBI. (But since 1970, summer temperatures at night have increased by 3F on average, which means that people get less suspended at night.)
“In addition to rest, the body must rehydrate,” said Reischl, adding that people should drink more water than they would normally do.
What can people do to alleviate thermal stress?
Avoid intense outdoor activities, drink liquids, get away from the sun and spend more time in air-conditioned places such as cooling centers.
What are the means to stay cool without AC?
Putting your feet in cold water, placing fresh towels around your neck, sitting in front of an electric fan and sprinkling water on yourself is effective ways to cool. Just like the nuances at home during the day and the windows to open at night.
