Let's make a chart of what effects occur at which cold temperatures

[What the deuce?]

I was inspired by this (http://www.xkcd.com/526/) comic which tries to make a chart of temperatures (e.g. "45C/113F" is "Dubai heat wave", "-40C/-40F" is "spit goes 'clink!'"), etc.

So, at what temperatures do various things happen? For example, at what temperature does it become hard to breathe? Danger of death with no clothes on? soap bubbles freeze (http://www.youtube.com/watch?v=OM9WXrGftXE&feature=related) in mid-air? I'm looking for effects, not statements like "that's how cold Fairbanks is", though I guess you can use that if you really want to.

Make sure to specify F or C.

I ask this because I can't "imagine" temperatures below -5 because that's the coldest I've ever experienced (this morning, not surprisingly). I don't know what extra effects kick in.

Here's a couple to get started:
-75 F: becomes very difficult to breathe (video (http://www.youtube.com/watch?v=rZjfScL_wRE))
-40 F: boiling water thrown in the air becomes "snow" and doesn't hit the ground. I'm not sure if this occurs at lower temperatures also.
32 F: water freezes
?????: urine freezes before it hits the ground
?????: spit freezes before it hits the ground.
?????: too hot to walk on the ground barefoot (we don't just have to do cold, you know)

[Sunspace]

-18C: My nose hairs freeze two breaths after I go outside. :)

[Jenaroph]

Aww, I was gonna say snot freezes, only I'd say it as 0°F.

[What the deuce?]

-18C: My nose hairs freeze two breaths after I go outside. :)

I don't know where you're from, but I was outside for about a half hour when it was -20 C (-4 F) yesterday and my nose hairs didn't freeze. :)

[Boyo Jim]

Shrinkage... you guys know what I mean.

[Napier]

>Make sure to specify F or C.

Mercury freezes near -40. And, yes, I will specify. That is F or C.

[Athena]

-17 F, Vodka freezes.

[lobotomyboy63]

-40

Boiling water freezes in mid-air, Antarctica

http://www.youtube.com/watch?v=jsPHr8uR6ig

The video title doesn't say C/F, but then, -40 is the point where the scales intersect, so take your pick!

[Harmonious Discord]

-10F Tires have a flat spot until you drive a mile down the road with a bounce in the ride. It's like your on a bumpy road.

-10F Vehicles without 5W oil don't crank over fast enough to start regardless of the charge in a battery.

0 Things you use outside break. You have to fix something new every day.

-10F Transmissions are very stiff and putting the vehicle in gear can kill the engine.

0 The plastic lens in glasses shrink so much they fall out of the wire rims.

Below 0 vinyl cracks, so your auto interior can break when you sit or hit it by throwing something on it.

[Canadjun]

-40 - It doesn't matter whether you are American or Canadian.

[ASAKMOTSD]

<anything>F below zero - all feels the same - painful

[AuntiePam]

I don't know what the temp was -- maybe minus 30F -- but at that temp a banana will freeze so hard that you can use it to pound nails into a board. A local news guy did it a couple days ago.

Oh, and at minus 30F, the newspeople will film outdoors because unless we actually see them out in the cold, we won't know it's cold.

[Tastes of Chocolate]

0ºF - snow crunches when you walk on it.
0ºF - nose hairs freeze when you breath.
-25ºF - Nylon coat liners get stiff and crinkle when you move.
+20ºF (after -25ºF) People celebrate and run around without coats.

[Leaffan]

Salt (NaCl) doesn't work very well as a road de-icer below -18C.