It is approximately as cold as a well-digger's hinder parts in January here in Indy -- and that's cold, since, you see, the temperature at the bottom of a well is pretty much the same year-round and old-fashioned wells took a degree of maintenance, so the well-digger was warm enough on the job, but when he climbed back up on a cold Winter's day, usually soaked the the waist, he was gonna be a lot colder than everyone else.
Where was I? Oh, yes, it's so cold now that if you spit out a second story window, it's turned into a an iceball on the way down and shatters when it hits -- and it's got to be awfully cold to tempt me to spit in public.
Naturally, I have been using those chemical handwarmers (and if you don't, you should: they're wonderful!). You pop a couple of 'em out of their air-tight packages, stuff 'em in the pockets of your second-layer garment, layer on over that and your core stays toasty warm. It's a huge help!
But how do they work? I fell to wondering what the end-product(s) of the exothermic reaction might be. Can you have a bunch of them warming your car? Could my friends who work on the big starships of the Hidden Frontier stuff 'em in their pressure suits when working in the colder holds? Yes, as happens, they could. Chemical handwarmers work by rusting! More or less.
Ha ha, you say, that's a joke from High School Chemistry, all oxidation is "rusting." Nope, it ain't and yes, this is. Okay, they sneak in a catalyst to make it go faster and some other odds and ends to keep it from going too fast, but the stuff that's doing the work is iron becoming iron oxide. Which is pretty nifty. Also nifty: you can stop and start the reaction. All it takes is a decent zip-lock bag: stick the handwarmer in it, squeeze out as much of the air as you can and zip it shut. Once the remaining oxygen is used up, it cools down and is ready for the next use. Since some versions will warm for ten hours, it's useful to be able to save that warmth for later. Funny, they don't so much mention that in the directions on the label.
These things are a must for a "just-in-case kit" for your car, or for a Winter bug-out bag. Made of win!
1. However, a version of the mechanical counter-pressure suit is the most common pressure suit, at least in Anglophone space, so there would be some details to work out to get oxygen to the warmers. I should ask -- the actual fix may be as simple as electrically-heated motorcycle oversuits, bought right off the rack. Plus, most parts of the starship, the problem's too much heat, not a lack of it.
2. The Data Viking is snickering as he reads this, remembering that I got through Chem class on glibness and last-minute memorization, whereas he showed a remarkable aptitude for the subject.
5 months ago