On the subject of yellow snow: Would putting a bit of snow in a suitable container and then peeing on it (obviously if it wasn’t so cold you’d get frostbite) be an efficient way of melting it, re-using lost body heat and replacing salts?
Keeping a bag of snow in your pocket is pretty much as bad as eating the snow. Your body heat is still being used to melt the snow. Some of it will be excess bodyheat that would otherwise escape but the majority is going to be additional heat to counteract putting snow next to your body.
The biggest problem with eating snow IMO is that it’s a slow and annoying process that keeps you from doing other things to take care of yourself. Melting snow is definitely preferable but if eating some snow is going to put you over the edge to hypothermia you’re pretty far gone already.
In the short term, eat snow to keep hydrated. If you’re going to be stuck for days, figure out how to start a fire and find a pot.
I’d never heard that one is not supposed to eat snow.
I have eaten it on several occasions, in Australia and New Zealand. Only small amounts though.
Never heard of this. I’m from the Netherlands. It does snow, but if you’re stuck in the snow in a forest you go to the nearest “Pannenkoekenhuis” and have a pancake. Sometimes it pays to be from a small country.
That certainly sounds a lot more useful, and warmer, than heading downhill until you find a stream and following it down 
OP here. Just want to address the primary questions (sorry for the long delay, it’s been a busy week).
First, this scenario is a survival scenario. It’s not a situation where you are outside skiing/snowshoeing/sledding for a day and you’re a bit thirsty and chomp on some snow. Generally, there won’t be an issue with eating fresh snow from a contamination perspective if you use common sense (don’t eat yellow snow, don’t eat old snow, don’t eat snow surrounding a parking lot, don’t eat snow that obviously has snow fleas, etc.). I eat snow in the winter too - skiing all day, at the top of the mountain, mouth is dry, really warm, grab a chunk to cool off and get the mouth a bit wet.
However, if you are potentially in a survival situation where you’re in the mountains for a number of days or weeks (as in the scenario), melting snow prior to drinking is crucial. As said a few times, snow is full of air. You could inadvertently dehydrate yourself eating snow all day and only getting a few cups of melt in your body. But the big driver is avoiding hypothermia. Not only are you possibly reducing your body temperature externally (i.e. cold ambient temperature, working up a sweat and cooling off, etc.), eating cold snow can work towards hypothermia internally. Yes, in a survival situation, even 0.1 C of temperature drop DOES matter - it can set you over the edge. Once you kick off that first domino, it’s difficult to stop the effect if you don’t have the right skills or equipment (and especially if you’re alone).
Here are a few links from outdoor/survival sites mentioning that you should not eat snow in survival situations:
Page 56 of the NOAA Guide to Survivalstates: “Eating snow or ice is not recommended. The amount of energy required for the body to melt the snow and use the water outweighs the benefits. In addition, eating snow in a weakened condition can contribute significantly to hypothermia…”
NOAA Winter Safety Brochure
Wiki on Outdoor Survival
CDC Website on Winter Weather Survival Advice
Hope this answers some of the questions!
If you eat the snow to prevent dehydration and your body temperature starts going down as a result, would pissing on one another warm you up again?
eh, wot? 
They’re second cousins to type lice, twice removed for tracking mud on the carpet.
Thanks, I never knew such thing existed.
Apologies about the OT nature of the question.
Southern California here. I, too, upon reading the term “snow fleas” said to m’self…
“WHAT THE FUC&@NG SH%$?!”
:eek:
This doesn’t make any sense. Snow is just ice… spread out a little. Eating snow isn’t going to be any worse than eating ice. The cold air trapped in the snow has a very low heat capacity and won’t affect you any more than just breathing the cold air normally.
I’m with this being nonsense as a general statement. It could easily be the case that you have warm clothing and sufficient food, but no means of creating fire and no other water supply. In that case it would be vital to consume snow to prevent dehydration. Eat the snow slowly enough and there will be no significant effect on your temperature, and you can increase your food supply to compensate for the extra energy needs.
I once walked all the way to the corner store and back, in January at –20 F and snow three feet deep, without having to eat snow. Hell, I wasn’t even thirsty.