On the subject of staying warm, here’s the other thing that has made a revolutionary difference for me: hot packs, the commercially available kind that are made of very basic ingredients that heat up when exposed to air. They don’t get prizes for sustainability or minimal cost, but they’re also not horrifying on either count. For me they’ve made the difference between shivering and being comfortable, over and over.

There are at least a couple of different brands of these things, but the basic ingredients are similar, and simple: iron powder, water, salt, charcoal and vermiculite. These materials are combined in individual packets sealed in plastic wrappers, and when opened, the contents begin oxidizing and producing heat. Apparently the technology has been known for many decades – I believe since the first world war. But prior to the widespread use of plastic it wasn’t practical, because once made it was almost impossible to store completely airtight, and in large quantities became a serious fire hazard. Personally, I’d prefer to have a world with no plastic and to live without these hot packs, but since plastic is everywhere anyway, the hot packs sure are nice.

My preferred brand is “Hothands Body & Hand Super Warmer,” which has virtually no odor, and heats for well over 12 hours (the package says 18). Another brand, which is what one gets if ordering from Campmor, is called “Grabber MyCoal.” This one also works, but it has more of a smell, and the old ones I used to get from these folks didn’t last nearly as long. The Hothands version is available on the Internet, and the cost comes down if you get a case of 40. http://www.amazon.com/HeatMax-Hand-Body-Warmer-Count/dp/B0007ZF4Q8 (Including this link for convenience, because the array of choices can get confusing. Like always, I am unaffiliated and not receiving anything for the reference.)

The packs can get quite hot – enough to get burned if you leave one against your skin – so it can be a good idea to put the packet inside a fleece sock or hat, and to pay attention to not leaving it against your skin if you’re going to be sleeping. Speaking from experience, it’s possible to wake up with a burn if you’re not careful about this!

Being a chemical reaction, it is sensitive to conditions, and its performance will vary accordingly. Mainly, it’s initially surprising how much air is stopped by various pieces of clothing. I once put the little handwarmer version inside big ski mitts with shells, whereupon the warmers stopped working completely. And when Dave and Anke were on the boat last year I carefully warned them about not getting burned, and then Dave said that his was just nicely warm, but not hot enough to think that there might be a problem. I puzzled over this, and later realized that the pocket where he had the hotpack was underneath an outer layer of coated nylon rain pants – apparently relatively air-proof! Those pants are the same ones I was using this year, and I had the same experience. Placed with better air access, the hot packs heat right back up.

Because of the air issue, it’s easy to “turn off” these warmers, to save them for future use. I have often started one in the early morning, and once the sun has been up for some time everything (including me) is then comfortably warm and it’s no longer needed. (AUKLET’s windows are outstanding for passive solar heating.) In order to get a good seal for “turning off” the warmer, I save one of the original packaging envelopes, put the warmer back in, fold the top of the envelope over carefully three times, pressing out the air, and then keep it closed with 2 or 3 paper clips. Once the pouch has cooled down, it then goes inside a Ziploc bag, also sealed, so there aren’t any slow leaks. I’ve come back and used these again, after storing them this way for weeks, with total success. The Ziploc bag is handy for storing the paper clips and all, along with spare new hot packs, so it works out pretty simply.

These things are normally about a dollar apiece, and I used to think of them as extravagant, buying just a few, and saving for emergencies, or for times of serious discomfort. Eventually I thought “what would this look like, if I used them at will, whenever I was cold? How many would I go through?” So I bought a case of 40 last year, and tried to relax my inclination to hoard and save for more dire situations. Gradually I got the hang of that, and it was nice to be warm, especially in the middle of the night and early morning when the fire in the stove was long gone, or it hadn’t felt cold enough to start a fire in the first place. Sometimes I even used two – one for cold feet, and one at my belly for overall warmth. They were especially useful during times of having been out in the cold for ages, and getting warmed up again. Eventually I learned to put one in the foot of my sleeping bag while I was still out, so there would be a warm place to come back to for cold feet.

Surprisingly, even with all this extravagance, and last year sailing long into the New England fall, the most I’ve gone through is about a case and a half in a season. This year I started with one case on the boat, and another stored at home. Only being out for four months, and much of that in the summer, I came home having only used a bit more than half of what I brought. As far as I’m concerned, this is a complete success. In the big picture, for four – or seven – months of onboard comfort it’s been quite worth it. Even when I choose not to crack one open, there is relaxation in knowing that I could. It’s just not necessary to be so cold.

Quite a number of years ago – 25, in fact – I lived outdoors in the US southwest, during the winter. This was because of chemical sensitivities, in combination with lack of resources, and it didn’t always go so well. For one thing, the desert can be quite cold at night in December and January. Outside of Tucson, where I was for one of those winters, the temperature went into the low 20s. For occasional winter backpacking, this is nothing. But it’s a different story when you live with it, and have been chilly day after day.

One particularly cold night I was in my sleeping bag under the crazy shelter that was serving as home, shivering. I remember telling myself that even though I was shivering uncontrollably, which meant that this was the beginning of hypothermia, that nobody dies of hypothermia inside a dry sleeping bag, out of the wind, with the temperature in the 20s (turns out it was 13° that night). Nowadays I wonder if that was true, that nobody dies in that situation, but the thought comforted me at the time, and in fact morning came and I was still there.

This story is a tangent – obviously not sailing – but I think it’s the reason that I am so utterly devoted to these little hot packs. With a good stash of these things on board, there will be no repetition of that kind of night. It’s nice to be warm.