[Low-Tech] [High-Tech] Portable cooling: higher-TL replacement of water jugs?

[Flyndaran]

Whoops, I read 12 degrees as F, not C.
Yeah, horrible mistake on these global forums.

That's quite a huge temperature difference for slow evaporation.

[Verjigorm]

Originally Posted by Agemegos

When the weather is hot my dog (whose mass is about 36 kg) begs for cold water from the fridge, which at 2 C is about 36 K cooler than the core temperature of an uncomfortable dog. If he were to drink 400 ml of it (which I reckon he often does) that would be 1/90 of his mass, and sufficient to cool him down by 0.4 K. That is certainly enough to be physiologically significant.

Suppose a 68 kg man drinking half a litre of water 12 K cooler than today's ambient temperature hereabouts, which is 28 C in the shade. That's 16 C compared to say 37 C core temperature of a heat-distressed bushman: 21 K times half a kilo over 68 kg = 0.15 K. Not a huge amount, but physiologically significant.

I often work in 100 degree(farenheit, cuz I'm 'MURICAN!), high humidity(80-90, with close to 100% on many days), doing physical labor in an unventilated warehouse. Before they outlawed camelBaks at work, I would fill mine with ice and water, and just taking a sip was a big, big deal.

[Flyndaran]

Originally Posted by Verjigorm

I often work in 100 degree(farenheit, cuz I'm 'MURICAN!), high humidity(80-90, with close to 100% on many days), doing physical labor in an unventilated warehouse. Before they outlawed camelBaks at work, I would fill mine with ice and water, and just taking a sip was a big, big deal.

I'm sure it felt that way. But it would take scientific analysis to separate physical cooling from almost as important psychological morale improvements.

[Agemegos]

Originally Posted by Flyndaran

I'm sure it felt that way. But it would take scientific analysis to separate physical cooling from almost as important psychological morale improvements.

And rehydration, as you mentioned before.

[Flyndaran]

Originally Posted by Agemegos

And rehydration, as you mentioned before.

Of course, but Gurps already has rules for dehydration. It's just the +1 survival from cool water that comes off a bit odd.

[vicky_molokh]

Originally Posted by Flyndaran

Whoops, I read 12 degrees as F, not C.
Yeah, horrible mistake on these global forums.

That's quite a huge temperature difference for slow evaporation.

Actually, in the sources I've found, it wasn't clarified whether it was 12°C, K, or °F. Having it be °F would further halve the impressiveness of the mechanism!

[vicky_molokh]

Originally Posted by Verjigorm

they outlawed camelBaks at work

Why would they be made outlawed?

[Verjigorm]

Originally Posted by Flyndaran

I'm sure it felt that way. But it would take scientific analysis to separate physical cooling from almost as important psychological morale improvements.

Well, let's think about it. I'm about 165lbs, so that's 75kg, right? About 70% of me is water, so that's what, 52 liters or so? During the summer months while working, consuming 2 to 4 liters of water in 5-6.5 hours was a regular thing, with few breaks to urinate. That's about 3-5% of my total water content in a work period. And I would have considered myself poorly hydrated through-out that period.

Yes, if we're talking about a few ounces of cool water, that's no big deal. But if we are talking about multiple liters of water consumed and lost, then that's a pretty significant amount of my water mass. But over a day, you need to consume about a gallon and a half of water to be healthy. GURPS lets us get away with what, 2 quarts day? Which is a half gallon, which is about on the minimum I would put back for a day if I suspected potable water to be hard to come by.

Speaking of those shifts, when I think about it, I'd be taking something like 10-13 HT checks at -2 over the course of a shift. Of, and depending on how you'd like to asses penalties for exertion, say 1 or 2 fatigue per hour. Which doubles up quickly in near hundred degree heat.

In that kind of heat and humidity, you sweat copious amounts of water, so when you have a moment to pause, you drink massive ammounts of water. Consuming 20 ounces at a time is routine, heck, downing 20 ounces, then filling it up with cold water from the fountain and guzzling that is a normal thing. Then right back to work.

But yeah, a bonus to survival and FP loss due to heat is probably due. After-all, if I'm losing 1fp an hour due to work, and that was doubled by the heat, then that's 10-12 FP lost over the course of the night, without failures on that check at -2 every 30 minutes. So either I have really good health, or water helps.

[Verjigorm]

Originally Posted by vicky_molokh

Why would they be made outlawed?

Something about a security risk. Which is terrible: working in an unventilated warehouse moving packages at those temperatures causes you to sweat a huge amount. Having a hands free way of accessing your water, as well as keeping it cool is just absolutely clutch.

[Anthony]

The amount of heat from water that is 12C cooler than you body temperature is just over 2% of the amount of heat you'll eliminate by sweating away the same amount of water, so in absolute terms it is not significant. However, it's cooling available exactly when you want it, and not subject to the limitations of sweat (which can shut down in cases of heatstroke).

In fact, the bonus to survival might really be a bonus for having heat stroke treatment available.