STORY: Hotter and hotter temperatures are being recorded around the world.
“I cry all the time, I yell it, yell at the heat to like go away.”
But climate experts say just looking at the air temperatures alone can be misleading.
It’s the “wet-bulb” temperatures they’re particularly worried about.
Wet-bulb temperature is a measurement that accounts not just for air temperature – but also for how much moisture it holds.
"Wet bulb temperature….”
Matthew Huber is a climate scientist.
“So it's the minimum temperature that can be reached for a given set of temperature and humidity conditions.”
When both - humidity and air temperatures are high - it makes it harder for us to sweat... and humans lose around 80% of heat through sweating.
That results in overheating.
And it could cause serious health effects if people can’t find a way to quickly cool down: including respiratory and cardiovascular issues - or even death.
Huber says it would take several hours at a wet-bulb temperature of 95F to cause serious problems.
Some scientists argue the threshold is even lower.
“If the wet bulb temperature is hotter than what would allow you to lose that heat, then you're you know, it's, it's like somebody has cut off your main way of cooling. It's like somebody wrapped a wool coat around you in the middle of the summer. So, once you lose that, you have serious problems losing heat.”
People who live in tropical regions with a lot of humidity are most at-risk.
China, India, Bangladesh, Pakistan and Africa's Sahel region are all considered key risk zones.
Jacobabad in Pakistan — dubbed the hottest city on Earth — has surpassed a wet-bulb temperature of 95F on at least four occasions.
Climate change may also cause dangerous wet-bulb temperatures to last longer.
Dangerous wet-bulb temperatures could persist for six or more hours by 2060, according to a recent study in the Journal of Scientific Advances.
That would kill anyone who can't take cover.