Water chill factor

[dumpsterDiver]

The difference is that air warms up quickly around your body if there is little air movement. that is how clothing keeps us warm. Water has a much higher heat capacity and the conductive heat loss is also much faster than air (like 25x) so i would think that unless the water was super still and you were stationary, still water would not chill a whole lot slower than moving water (assuming you have no clothes on) . If you wear thick clothes in moderately cool water, the water against your skin will warm up a lot if you are super still. You can notice this effect when you start to move and you pump the warm water away from your skin and bring in fresh cool water.

 

[Akimbo]

If wind chill can be calculated, then why can't water chill be calculated? I'm a simple person and I can't figure it out.

Wind chill is a function of air moving, but you said the water was static??? So what exactly are you asking for?

At what temperature does static water conduct heat at the same rate as static air at a X temperature?

 

[Festus]

Mini me retreats from cold water. He rarely feels cold air.

 

[drrich2]

evad:

I suspect part of the reason we don't have an answer is that absent a practical use for the info., there's not that much incentive to find out.

On land, in air, people vary in their temperature preference. For example, before I had too much food the past day or 3, I tended to weigh about 275# at 6'1" tall. Beefy, broad-built, fairly long-torsoed guy. Some of my coworkers are women, with substantially less bulk. Guess what?

I prefer a room temp. around 70 - 71 degrees. They prefer around 75 or so. Depends on how accurate you think the thermostat.s are. Temp. Wars are alive & well at my workplace. I tend to win...

In the water, I'm okay with shirt & trunks, no wet suit, down to 76 degrees, which I find rather chilly (I can do 75). I can do water in the mid. to upper 60's with a 5 mm full wetsuit. Put a hood & gloves with that, and give me warm surface water & a couple of thermoclines to acclimate through & get warmer water into my suit, and I can drop down into 45 degree water for awhile.

There are women who wear full wetsuits, even like 5 mm, in 80 degree water!!! I have a lean, athletic & small male buddy who switched from a 3 mm full suit to at least partial 5 mm coverage on a Bonaire trip with repetitive diving.

My point is that a few degrees in the water makes a much bigger difference than it does in air, and individual variation in temperature preference varies much more widely (or so it at least seems to me).

I'm also not sure the science involved would work. Let's say you put the average man in casual attire in a 45 degree room. That's cold. At some point, his production of body heat will equal his heat loss. Probably via shivering, significant discomfort and with peripheral body cooling, but because heat loss in air is more gradual he can do it.

For comparison's sake, you want to know what water temperature is equivalent to 45 degrees air (without wind). At what point? Is it how cold it feels when you 1st jump in? How much heat loss you have at the 15 minute point? Or 30 minute point? If these measures aren't all consistent with what you'd see in the air comparator, I don't think you can make a good comparison. The 'water chill factor' might differ over time. So if 70 degree water felt equally cold to you when you jumped in, it might feel much colder after 20 minutes vs. the 45 degree air on land.

Richard.