Ryan Handson
Global warming is real and temperatures are rising across the globe – but you already knew that. And you probably already know what that means for the environment, but do you know what it means for the human body? Scientists are using something called wet-bulb temperature to measure exactly that – and it’s not looking good for humans.
What Is Wet-Bulb Temperature?
When you read a thermostat, you’re reading what’s called a dry-bulb temperature. There’s also such a thing as a wet-bulb temperature, which takes into account the humidity levels and helps us measure how well we’ll be able to cool ourselves by sweating.
You can measure the wet-bulb temperature by placing a damp cloth over the bulb of the thermometer. The water from the cloth evaporates and cools the thermometer down – which mimics how the human body uses sweat to cool itself down.
Maintaining A Healthy Internal Temperature
A lot of people forget how important body temperature is to the overall health and function of the human body. In a perfect world, our body temperature would rest somewhere between 97.5 and 99.5 degrees Fahrenheit – or 36.4 and 37.4 degrees Celsius.
When the body can’t warm itself up in cold and freezing enviornments, the possibility of developing hypothermia increases. When the body can’t cool itself down in hot and humid environments, the possibility of developing hyperthermia increases.
When We Get Hot, Sweat Cools Us Down
When the human body starts getting hot, it produces sweat to cool itself down – similar to the wet-bulb effect on the thermometer. As the water in the sweat evaporates, the surface of the skin cools – ensuring we maintain a healthy body temperature.
Sweat evaporating on the surface of the skin accounts for roughly 80% of the cooling of the human body. This is because evaporation requires heat – so when the body evaporates water, it uses excess body heat, which cools the body down.
As Humidity Rises, Evaporation Declines
The human body can tolerate a heat wave and it can tolerate high humidity levels, but problems start to arise when high humidity is paired with rising temperatures. When this happens, water evaporation declines and the body struggles to cool itself down.
This is called the wet-bulb effect, and it’s usually characterized by a wet-bulb temperature of 95 degrees Fahrenheit (or 35 degrees Celsius) – in other terms, 104F (40C) with 75% humidity. In these conditions, body temperature will rise to a point of no return.
Overheating Often Results In Death
Overheating, also known as hyperthermia, can have a lasting effect on a person’s respiratory and cardiovascular health. Some of the most common signs include goose bumps, a tingling sensation in the skin, a dull headache, and nausea.
According to recent research, the human body can survive for about six hours once the wet bulb effect begins. If our bodies don’t cool down within those six hours, we risk death. Unfortunately, that’s a harsh reality for many people in the world right now.
India Endures Massive Heatwave
Over the past month, several parts of India – including West Bengal, Odisha, Jharkhand, and Bihar – have been trying to overcome a massive heatwave that has temperatures as high as 115 degrees Fahrenheit (46 degrees Celsius).
The heatwave began in mid-April and has continued ever since, though temperatures are expected to decline in the next week. Until then, Indian citizens are doing whatever they can to stay cool and stay away from the crippling heat.
TV Presenter Collapses While Working
On April 21, Lopamudra Sinha – a news anchor with the Kolkata branch of Doordarshan – was providing an update on India’s heatwave when she started slurring her words. She fainted and blacked out moments later – while live on air.
“The teleprompter faded away and I blacked out… I collapsed on my chair,” she said in a video shared on Facebook. She blamed her health scare on the intense heat and her blood pressure suddenly plummeting while reading the teleprompter.
Temperatures Rise In Mali and Burkina Faso
If you thought India was bad, wait until you hear about the temperature in Mali and Burkina Faso – as well as other countries in the Sahel region and across West Africa. They experienced temperatures as high as 118 degrees Fahrenheit (48 degrees Celsius) in March and April.
The beginning of April was the worst of it, with the Gabriel Toure Hospital in Bamako, Mali’s capital, reporting 102 heat-related deaths within the first few days of the month. Most of those deaths were adults above the age of 60.
Near-Wet-Bulb Conditions In Persian Gulf Last Year
The Persian Gulf is preparing for what could be another hot summer after cities from Dubai to Doha experienced near-wet-bulb conditions last August. Some cities have already experienced extreme weather conditions this year – albeit in the form of rain.
On April 16, Dubai saw a year’s worth of rain fall in a matter of 24 hours – turning airport runways into a lake and flooding the metro area. Where there’s rain, there’s almost always humidity – which is concerning with the summer months quickly approaching.
More Humid The Air, Faster Temperatures Will Rise
According to bne IntelliNews, this year’s record rainfall is indicative of what’s to come in the Persian Gulf and other areas around the world. Unfortunately, hotter temperatures mean air can hold more water, which translates to more rain.
In fact, with every one-degree rise in temperature, water vaporization increases by 7% – meaning the more humid the air, the faster temperatures will rise. If temperatures and humidity levels rise too much, people could start dying in large amounts.
Which Countries Have Passed The Wet-Bulb Threshold?
Some of the most at-risk countries when it comes to wet-bulb conditions include China, India, Bangladesh, Pakistan and Africa’s Sahel region – some of which have already flirted with wet-bulb conditions this year.
Jacobabad in Pakistan, sometimes referred to as the ‘hottest city on Earth,’ has passed the wet-bulb threshold four times. La Paz, Mexico, Port Hedland, Australia, and Abu Dhabi, UAE, have also passed the threshold.
3 Billion People Will Live In Uninhabitable Countries By 2070
In another report by bne IntelliNews, researchers estimate that roughly three billion people will live in countries deemed uninhabitable by 2070. For reference, there are only 8.1 billion people in the world today.
And if you’re wondering why, climate change and global warming are perhaps the biggest culprits. “That’s why people are sort of talking about [wet bulbs], because a very humid heat wave is a lot more dangerous than a very dry heat wave,” said Rachel White, an atmospheric scientist.
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