What is the effect, high humidity in the air, for humans?
In: 1
The moisture in the air can condense in your lungs and cause you to literally drown on land. Don’t worry about it too much. The humidity has to be really close to 100% so it really only happens in certain caves
We cool by evaporation. Sweat evaporates and pulls heat along with it. Humid air is already wet and can’t absorb as much moisture as dry air making evaporative cooling not as effective making us hotter .
Our body’s most effective means of cooling down is by evaporating water. We do this by sweating, covering our skin with water that takes energy from us in the form of heat when it “boils” off.
If there’s a lot of humidity in the air, our sweat won’t evaporate as fast, and if the humidity in the air is 100% it won’t evaporate at all, meaning we cannot cool down and heat stroke is inevitable.
Other than that it doesn’t affect much. Our skin gets less dry. It may increase the risk of certain types of skin infections because fungi and bacteria need moisture to survive.
It prevents our body from cooling. We eliminate excess heat through sweat thanks to a process known as evaporative cooling. Basically, when water evaporates off a surface it brings a little heat with it, resulting in that surface getting cooler. But if air humidity is high, evaporation cannot occur, because the air is already saturated. That means evaporative cooling cannot take place and our body begins to overheat.
Which brings us to wetbulb temperature, ie. the temperature measured by a thermometer wrapped in a wet tissue. If the air is dry and evaporation occurs, a wetbulb thermometer will measure an air temperature several degrees lower than the actual temperature you would measure with a regular, “drybulb” thermometer. If moisture is very high, evaporation won’t be as efficient, and the wetbulb temperature will be closer to the drybulb temperature.
A wetbulb temperature as “low” as 35°C (96F) results in a fatal heatstroke. Such value has only ever been reached a couple of times in the Persian gulf and in Pakistan, thankfully in mostly uninhabited areas and for short amounts of time. But global warming is making wetbulbs rise, and there is legitimate concern that sooner or later the 35°C wetbulb threshold will be reached in a major settlement, causing thousands or maybe millions of people to just drop dead.
Latest Answers