Experts are raising the alarm over steam pressure in the hottest season on record, with scorching problems killing life from India to Mexico and Greece in its earliest heat.
The state kills more people than hurricanes, floods or any other climate- related great, but what is heat stress simply, and how is it measured?
– ‘ Silence criminal’-
When the brain’s normal heating systems are overheating, heat stress results in symptoms ranging from headaches and dizziness to instrument failure and death.
It is brought on by prolonged exposure to heat and other economic factors, which up cause the body’s inner thermometer and ability to regulate temperature.
” Heat is a silent killer, because signs are not so easily visible. The consequences can be very bad, even catastrophic, according to Alejandro Saez Reale of the World Meteorological Organization ( WMO).
Infants, the elder, persons with health issues and outdoor workers are particularly prone. Residents of cities who live close to concrete, brick, and another heat-absorbing materials also run a higher risk.
The WMO estimates that temperature kills about half a million people annually, but it claims the true toll is unknown and could be 30 times higher than the most recent data.
People on the planet will be extremely exposed to situations that test the limits of human perseverance as weather change makes wildfires longer, stronger, and more regular.
– More than a utmost
Heat might be the most commonly used and readily understood weather indicator, but headline-grabbing “maximum peaks” do not fully account for how heat does affect the human body.
For example, the same temperature can feel very different in one place versus another: 35 degrees Celsius ( 95 Fahrenheit ) feels much different in the dry heat of the desert versus the humid climes of a jungle.
To create a more complete image, scientists consider a host of factors including heat but even humidity, wind speed, clothes, clear sunshine, and even the amounts of concrete or greenery in the area.
All these play a big role in how the body perceives, and most importantly responds to, extreme heat.
Some methods are decades old, while others distill a number or graph of the various environmental readings into one. There are also many methods to measure heat stress.
– ‘ Feels like’-
Wet-bulb temperature is one of the oldest methods available. It is a useful gauge when the thermometer reading may not seem excessive but when combined with humidity, it becomes intolerable, even fatal.
A healthy person can die in 2023 from just six hours of being exposed to 35 degrees Celsius and 100 percent humidity. Above this limit, sweat cannot evaporate off the skin, and the body overheats and expires.
Copernicus, the EU’s climate monitor, uses the Universal Thermal Climate Index ( UTCI), which considers temperature and humidity but also wind, sunshine and radiated heat to rank heat stress levels from moderate to extreme.
Extreme heat stress, as judged by this index, is a “feels like” temperature of 46 Celsius and above, at which point it is necessary to take action to avoid health risks.
The Heat Index, used by the US National Weather Service, offers an “apparent temperature” based on heat and humidity in the shade, and a colour- coded graph denoting the likelihood of illness from exposure.
The Humidex rating, created in Canada, combines heat and humidity into one figure to reflect the “perceived temperature” and presents the risk associated with each in a four-step “guide to summer comfort” chart.
– Limitations-
Other examples of” thermal stress” indices include the Tropical Summer Index, Predicted Heat Strain and the mean radiant temperature.
Heatwave expert John Nairn claimed some measures performed better in some climates than others because they are not without limitations.
” It’s not the same all around the world, about the way you approach it”, Nairn told AFP.
The UTCI, for example, is excellent at reading heat stress in Germany, where it was first developed, but” a very poor measure” in global south countries, he said.
It” saturates and measures far too much,” it says. And it would make those areas of the country more over-aware, according to Nairn, who has advised governments and the WMO on heatwave policy.
These locations might get better heat stress readings using wet- bulb temperature, he said.
These indices do not, he said, take the effects of heat beyond just the health of people, even though a heatwave could strand trains or overheat air conditioners.
” If your heat challenge is such that it gets to the point where your infrastructure is not going to function, and it starts failing,” Nairn said. This will have a negative impact on people who are no longer being protected.
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