I have long believed that quality hot water bottles and steel vacuum thermos bottles and are very valuable survival tools. They are a wonderful intersection of high and low tech that can serve in a number of helpful roles.
Fireless Cooking (retained-heat cooking) - I have cooked in WIDE-mouth thermoses many hundreds of times since the 1970s. There are a couple of other articles on this sight covering that fuel-saving application. I would amend the recommendation given re: Aladdin Stanley vacuum bottles, and I will cover that below. Using WIDE-mouth thermoses for “fireless cooking” is one very useful role for thermos bottles that saves fuel and allows mobility even while your food cooks. Summarized, fireless cooking in a wide-mouth thermos involves immediately transferring boiling-hot food into the thermos which is then sealed up for approx. two to three hours. It won’t burn or over cook the food. If the food temp drops over time into double digits fahrenheit, the food will eventually begin to spoil. If cooking grain, leave a half inch space empty at the top for expansion. If it is to be carried in a pack it should be maintained upright and placed within a plastic bag which can be secured against leakage. I’ve learned that the hard way.
Because of a long-term interest in vacuum bottles I have tested the heat-retention abilities of every brand I could lay hands on. The winner consistently is the Nissan stainless steel line with their premium vacuum technology marketed as “Thermax” insulation. “Thermax” is also available in the higher-end Thermos brand products, from the formerly American-owned Thermos Co. now owned by the same Japanese conglomerate that years ago acquired the Nissan line. (Not connected with the car company). Stateside, the Nissan products are marketed as Thermos-Nissan while the lower-end lines have the “Thermos” name as a stand-alone. The Nissan line incorporates tensilized stainless steel which allows them to be lighter weight than other metal bottles on the market while also being more thermal efficient.
The venerable, heavy old Aladdin-Stanley bottles worked pretty well and were built like a tank. Now they are Stanley-PMI, made in China, and their online reviews are deplorable. I have only tested the old A - S models which performed pretty well against the Nissans, for someone who didn’t mind the extra size and weight. Search out old, used American-made models and replace the pour-through stoppers with a solid stopper that must be removed to dispense the contents (available in some hardware and outdoor stores).
JWR Adds: Look for the older Aladdin-Stanley stainless steel bottles on eBay or through Craigslist. These are available with scuffs and minor dents for the fraction of the price of the new bottles , yet they are better made!
Having hot water readily available for warm drinks or for preparing instant foods throughout the day or night, whether at home or on the move, is a comfort and convenience. It may be more than just convenience in frigid weather. In a situation where hot water requires a wood fire – or, in some cases, solar devices -- having the ability to maintain a goodly supply of hot water for immediate use over extended periods without starting a new fire - or waiting for the sun - can be a treasure. Having hot water for washing first thing in the morning, before a fire is started, can be an invaluable comfort. Having hot water to refill a hot water bottle which you’re using to stay warm on a frigid night is another comforting convenience.
In a situation where starting a wood fire is necessary to heat water, having the means to store a gallon or more of hot water, without the fire start-up and fuel use, is a no-brainer, esp. when hot water is the only reason for burning the wood. (This is a scenario where having a “rocket stove”, e.g. the Stovetec, makes a lot of sense since the fire goes right into heating the water rather than also heating up several hundreds pounds of a woodstove’s steel and firebrick, something you especially don’t want to do in warm weather.) Working with a finite supply of any fuel, it makes good fuel sense to heat some extra water to put into a thermos rather than restarting a stove later on.
I have not found glass-insert thermoses that will perform anywhere near the efficiency at which high-quality steel units will function. Don’t throw the glass ones out if you have them, but be aware that there is a large performance jump with Nissan or the old Stanley steel units. Glass thermoses are, of course, considerably more fragile, too.
Two-quart thermoses will maintain higher temps for longer periods than one quart units so, for a family, a couple of these might be a wise choice. One ‘two-quarter’ is also a cheaper investment than two one-quart units. If it’s going to be carried in a pack though, choose what will make sense for you or your group.
The Thermos-Nissan one liter “Compact Bottle” thermos (FBB1000), besides being more efficient than the Stanleys (new or old), is also lighter weight and smaller. The Nissan WIDE-MOUTH “Food/Beverage Bottle” (FDH1405) is a 48 oz (1.5 qt.) unit as opposed to the Stanley’s one qt. which does not have a very thick stopper – the critical design element for maintaining heat long term in a thermos.
Efficiency of the any thermos can be increased by wrapping it with closed-cell sleeping-pad foam or other good insulating material. Concentrate extra insulation around the cap as this is where most heat is lost from a thermos.
DIY expedient thermoses can be made using a sturdy glass bottle thoroughly wrapped with closed-cell foam, Thinsulate, packaging foam, or various other insulators. An inner layer of heavy duty aluminum foil, shiny side in, will add the insulation factor of a radiant barrier which reflects heat back to its source. A radiant barrier needs a little air space between it and the hot object to work properly. A couple layers of onion bags (or similar open, lattice material) inside the foil layer should adequately meet this airspace requirement. Do not allow the foil any direct exposure to the surrounding air as this creates a point of conduction-convection heat escape. Over the foil is placed your standard insulation. All-weather duct tape should keep it all nicely intact. Preheat for a couple minutes with hot water, dump that out and fill with freshly hot water. If they are well-insulated these improvised thermoses may actually outperform some so-called thermoses currently on the market.
HOT WATER BOTTLES
Good quality hot water bottles (HWBs) can help with much more than pains, upset stomachs, and flu chills. They might even save a life in frigid situations. I would recommend two minimum per person, especially in cold climates.
One brand I’ve found to be particularly versatile is Fashy out of Germany. They make a tough thermoplastic hot water bottle that can resist repeated sanitizing in hospital sterilizers.
I’ve lived in cold houses where in winter I have sometimes gone to bed with two HWBs on nights some of which probably qualified as ‘Three-Bag Nights’ for those who remember the reason for having three dogs around you on such cold nights. With a good HWB (should have a very trustworthy stopper or be put inside a sturdy zip-lock bag) you can place near-boiling water in it and wrap it with terry towels to protect your skin and retard the bag’s heat emission so that it will provide heat for you throughout the night. Holding one HWB between the thighs may work as a good placement because most of the heat is transferred to the body. Against the spine and kidneys, backed up with a pillow, may work for side-sleepers. Experiment to find what works for you. If you haven’t tried a HWB (or two) on a cold night, you’re in for a real treat. Not quite as lovable as a couple of big, friendly dogs, but they’re a lot easier on the budget.
Diverging slightly here, in Chinese and Japanese medicine it has been known for centuries that maintaining the warmth of the kidney area of the back helps to maintain strength, alertness, resistance, and efficiency in the cold. Hara belts, scarves wrapped around the trunk to cover the kidneys, have been a common clothing accessory in these countries for centuries and are something for westerners to consider seriously (a German company called Medima, has nice, elasticized ones that are fashioned into a step-into garment). Our military has found the same benefits but adds the whole spinal column into the equation. There is clothing marketed now that is insulated with this awareness in mind and even has small behind-the-kidney pockets into which hand warmers can be inserted.
Strapping a HWB over the kidneys with a scarf inside a shirt may be a trick to consider in cold weather when a lot of movement is not anticipated. Putting the HWB inside the front of one’s shirt so it is bottom-supported above the belt may work with greater levels of activity. Experiment. Keep the stopper up (maybe padded, too) and remember the Ziploc bag if uncertain about the stopper’s integrity.
A back-up thermos of hot water can dovetail with this stay-warm trick to refill your HWB when it cools down to the point of not providing warmth. As with use in your sleeping bag or bed, near boiling water can be used providing the bottle is wrapped with a towel or other insulation which protects the skin and slows down the bag’s release of heat.
I look forward to hearing what tricks others have found for using these valuable tools for everyday use and survival applications.