I didn’t say eating snow could cause hypothermia, but that if you were at risk of hypothermia, say in a lost hiker situation, it could lower your core temperature. Survival experts recommend you melt snow and drink the water rather than eating snow for hydration.
I grew up in Wisconsin. After a nice fresh snowfall, we’d make simple sugar syrup by caramelizing sugar (there’s a fine line between sugar syrup and black-smoke-producing carbonized sugar–a very fine line), rush out the back door with the pot, and pour the melted sugar into fantastic squiggles in the snow, where it would instantly crystallize. Snow candy! Nobody every got sick from this.
I wouldn’t eat old dirty snow, but heck…unless you live next to the Union Carbide plant, this seems like an odd cultural taboo to me…
Why is this an issue? Eating snow is…fine. I get why a caregiver would stop their own kid, but a stranger’s kid? Leave it alone.
My general rule is not to correct random children unless they are in danger (i.e. eating large rocks and may choke, running into traffic), or really bothering other kids and the parents aren’t stepping in. Like if they are line jumping and other kids are waiting, or if they are hitting. Wait for the parent, if no parent arrives, a basic “let’s wait our turn” should suffice. Finger wagging is way over the line.
Generally, it’s not worth offending another parent or being an annoying busybody. This seems to be the norm