Living organisms can only survive within a certain temperature range. When the ambient temperature is excessive, humans and many animals cool themselves below ambient by evaporative cooling of sweat (or other aqueous liquid; saliva in dogs, for example); this helps to prevent potentially fatal hyperthermia due to heat stress. The effectiveness of evaporative cooling depends upon humidity; wet-bulb temperature, or more complex calculated quantities such as Wet Bulb Globe Temperature (WBGT) which also takes account of solar radiation, give a useful indication of the degree of heat stress, and are used by several agencies as the basis for heat stress prevention guidelines.
A sustained wet-bulb temperature exceeding 35 °C (95 °F) is likely to be fatal even to fit and healthy people, unclothed in the shade next to a fan;
at this temperature our bodies switch from shedding heat to the environment, to gaining heat from it.[7]
Thus 35 °C is the threshold beyond which the body is no longer able to adequately cool itself.
A study by NOAA from 2013 concluded that heat stress will reduce labor capacity considerably under current emissions scenarios.[8]
dohboi wrote:OMG, you guys still don't get it.
If wbt's are at or above 35, IT DOESN'T MATTER IF YOU'RE IN THE SHADE OR IN FRONT OF THE STRONGEST FAN EVER MADE, YOUR BODY CAN'T EVAPORATE SWEAT OFF YOUR SKIN, SO YOU COOK IN YOUR OWN SKIN AND DIE.
dohboi wrote:ambient wetbulb temps are at 35 or over.
dohboi wrote:At only 35 C (95 F) if humidity is 100% (called the wetbulb temp), the body cannot cool itself, no matter how much it sweats or how big of a fan you have, and no matter how little you move.
dohboi wrote:OS, you're just wrong, here.
The average fit, healthy person dies under those conditions withing about six hours.
And there is a big difference between 95% humidity and 100%. It's almost impossible to get 100% humidity.
Generally, "35 wbt" involves a hotter basic temperature with a lower humidity level. There's a chart somewhere out there to figure it out.
Do people think that I'm just making this shit up like KJ, or something??!! I have supplied many links to many very legitimate sites and studies.
Argument from incredulity is, well, it isn't an argument.
In normal circumstances, ie, anything below 35 wbt, yes, a fan will help.
But above that level no fan no matter how strong is going to cool you off one tiny bit.
Again, this is very, very basic physics here, folks. Fans normally cool you off because they increase evaporation rates of sweat off of your skin.
But sweat can't evaporate off your skin if humidity is 100% and your body surface is the same temp as the air.
It's a physical impossibility.
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