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I was talking to a friend and he said on his winter trips, he boils his drinking water before he heads out for the day and hikes in freezing weather. He said it keeps his water from freezing as fast.

In high school I was taught that hot water freezes faster than cold water. I use an insulated sleeve for my water bottles in the winter, this helps a lot.

I told my friend what I thought, and he said there's no way that's true and his water doesn't freeze fast at all.

Any thoughts or experiences you can suggest or enlighten me with? I want to clear this argument up for good, and neither one of us are going to accept each others ideas. What do the members of summit post have to say on this topic?

Hot water can freeze faster than cold water, but that's not always the case. To settle the argument the best thing to do would be treat your water as you describe (both you and your friend) and leave it outside (preferably not contacting any surfaces to accelerate heat transfer) and see which freezes first. That's probably the only way you'll settle the argument.

looks like these guys covered it

Gotta love thermodynamics.

DukeJH wrote:Gotta love thermodynamics.

yeah, you can't win, and you always lose!

When it's cold outside, say 20 F, and you throw boiling water into the air, it will turn to snow before it hits the ground, quite a fun trick. But, the same thing will not happen if you throw room temperature water into the air, in that case the water doesn't freeze fast enough and it just hits the ground as liquid water. I think that should be enough to rest your case.

During winter when resurfacing the ice at the Curry village outdoor ice rink in Yosemite valley I know that they used hot water along with the zamboni..........

lowlands wrote:When it's cold outside, say 20 F, and you throw boiling water into the air, it will turn to snow before it hits the ground, quite a fun trick. But, the same thing will not happen if you throw room temperature water into the air, in that case the water doesn't freeze fast enough and it just hits the ground as liquid water. I think that should be enough to rest your case.

If they both toss their water in the air, what are they going to have to drink?

Ahem, 20 degrees F isn't cold. In fact that was the high today here in sunny Crowley Lake. It is 3 degrees F right now, so I just boiled some water and threw it into the air and I got hot water all over my deck. Maybe that trick works at -20.

I was hoping it would freeze, then I could boil some milk, throw it into the air and I'd have Rocky Road ice cream on my driveway.

WoundedKnee wrote:To settle the argument the best thing to do would be treat your water as you describe (both you and your friend) and leave it outside (preferably not contacting any surfaces to accelerate heat transfer) and see which freezes first.

Since the goal is to prevent water from freezing during a hike, the experiment should try to replicate the conditions prevailing in water bottles during hikes. In particular, cooling should be slow and the containers should be closed and shaken as if they were carried in a backpack.

I grew up in the country near North Bay Ontario. Every winter the weather went down to -40 and stay that way for 3 weeks.

Well you know how your breath fogs in winter? In that cold, the fog would actually solidify into a breath balloon, and then fall into the snow like a light-weight soft rock.

The children played outside. We played tag, or snow-hockey, or just clowned around. But you know how kids yell when they play outside? Well the yells gelled as breath balloons, with the words frozen right inside them. They fell into the snow, and kinda layed around there. Then in spring, when they thawed, the racket of all those melting words was really annoying.

Greg Enright wrote:Maybe that trick works at -20.

It seems to work reliably around -40.

dan2see wrote:...Well you know how your breath fogs in winter? In that cold, the fog would actually solidify into a breath balloon, ...Well the yells gelled as breath balloons, with the words frozen right inside them. They fell into the snow, and kinda layed around there. Then in spring, when they thawed, the racket of all those melting words was really annoying.

That's pretty funny! If you're not careful, someone from warm country might believe this and pass it on, the beginning of another "internet legend".

On its way to becoming frozen, doesn't hot water have to become cold at some point?

Let's say that one bottle has water at 80 degrees and the other contains 60 degree water. As the temperature gradient between the water bottle and the outside air decreases (the water gets colder), the rate of change in temperature decreases. So the time it takes to get from 80 degrees to 60 degrees is less than the time to get from 60 to 40. However, the total time to get from 80 to 0 is still more than the time to get from 60 to 0.