One particular variable that is central to both of these topics is… heat. When you cook food, typically you are applying heat to your ingredients to fuse all of those individual ingredients into a singular delicious dish. In a survival situation, your core body temperature is one of the most crucial elements to staying alive. One of the key challenges in a survival situation is your ability to masterfully guide heat/cold toward or away from your body as needed to maintain your vital core body temperature. You might be surprised to discover that learning to cook (which by itself is a terrific survival skill) can actually help you develop an array of valuable survival skills… and learning how to maintain core body temperature in a survival situation can similarly help you learn to be a better cook! Keep reading if you would like to learn more about how!
To better set up our premise, let’s take a closer look at some basics regarding how heat works. You are probably at least generally familiar with these concepts, but bear with us for a moment as we lay a solid foundation for our case for cooking as a great way to learn survival skills.
A great illustration of how conduction,
radiation and convection work.
How Heat “Works”
As most of us know from basic physics, heat plays by a few “ground rules” that we can always count on. For example, heat has three modes by which it uses to transfer its energy:
1) Conduction (thermal transfer via direct contact), 2) Radiation (thermal transfer via motion of charged particles) and 3) Convection (thermal transfer via heat rising, cold sinking and temperatures circulating). These three modes are going to be key components in our equation.
Another key variable in our understanding of heat is that… 4) heat is part of the electromagnetic spectrum just like visible light is. This is also key in understanding how to manipulate this energy to accomplish our goals. This is just a brief list of the basics of thermal energy, but it’s enough to give us a lot of insight for the time being.
So let’s review our very basic list of takeaways regarding heat:
Heat is transferred via three modes:
1) Conduction (thermal transfer via direct contact)
2) Radiation (thermal transfer via motion of charged particles)
3) Convection (thermal transfer via heat rising, cold sinking and temperatures circulating)
4) Heat (like visible light) is part of the electromagnetic spectrum
Pictured above is a typical Dutch oven
setup. Notice how there are many
more coals on the lid than there are
beneath the oven to produce an even
heat. This is because of convection
Now let’s take these rules and apply them to our two topics (survival and cooking) and see if we can find any significant crossover. In cooking, knowing that heat generally rises (convection) helps us understand that our food item will tend to cook more quickly with a heat source underneath it than it will with a heat source above it. That fact is illustrated by the simple fact that, when cooking with a Dutch oven for example, it takes roughly a third more charcoal briquettes on top of the Dutch oven as it does underneath the Dutch oven for even cooking. This is just one example of this dynamic (heat rising) via convection.
|Conduction, radiation and convection all at work while
cooking. See the Pinterest pin source for this image here!
Conduction (direct contact) is the most efficient of these modes and has the quickest impact on your cooking. Pan searing is a terrific example of cooking with direct heat. Your food item is placed in a searing hot skillet and starts to brown and crisp on it’s surface almost instantly. The efficiency of conduction is further illustrated by the famous “grill marks” on your steak. Those brown grill marks are created when your steak makes direct contact with the surface of your metal grill grates. Despite the fact that those grill grates are heated up by the radiation of from your hot coals or gas flames and the rising convection from those gas flames or hot coals, where the grill grates touch your steak is where the extra charring occurs because the heat from the grates is hotter (and stays hotter) than the radiant heat or convection from your flames or coals. This demonstrates the efficiency of conduction over both radiation and convection.
Radiation is next on the list. While not quite as “efficient” as conduction in terms of heat transfer, radiation is a very effective means of heat transfer. Any time you cook something in your oven you are primarily using heat radiation to cook your food. While radiation is less efficient than conduction, it is a much more gentle way to cook your foods. This is preferred when you are cooking foods that have more mass. While cooking with radiant heat is slower, it allows foods with more mass or density to get to temperature more evenly. A medium-rare steak (seared on the outside but just warm on the inside) tends to do better with a conduction method of cooking (or high temperature radiant heat), but cakes, breads, casseroles etc. tend to require a gentler cooking method that promotes even cooking. Radiant heat is better for this. And whenever you are grilling and remove a burger or brat from the grill grate surface and move it to the upper shelf on your grill… you just switched from conduction cooking to radiation (and convection) cooking. Why do you do that? Because you know your meats are charred enough on the outside and you just want to keep them warm now, right?
Last but not least is convection cooking. Convection in cooking is primarily factoring into your cooking methods the fact that heat rises. Convection ovens take convection bit further by adding circulation of the hot air in your oven and circulating that hot air around your food to create a more even cooking temperature and faster cooking times. Convection in these ovens basically compliments the radiation that your oven’s heat coils have produced by circulating the heat around your food with a fan. Adding additional convection to an oven does make it more efficient, but convection is still not nearly as effective as a cooking method without an existing source of heat producing radiation.
You can see that heat (infrared light) is just to the right
of visible light on the electromagnetic scale.
Our last variable in this equation is the fact that heat, like light, is part of the electromagnetic spectrum. In fact… one could argue that heat actually IS light (heat is actually infrared light which is light that is just outside of the visible light spectrum). Understanding this dynamic and leveraging it can really help you amp up your cooking abilities.
The very best example that we can give you for this is the use of aluminum foil in your cooking. Why is aluminum foil such an effective cooking aid? Because it can actually REFLECT heat (or trap heat, depending on how it is used) much like a mirror can reflect light! So why does this matter? Whether you are baking a pizza, a casserole, a roast, meatloaf or prime rib, aluminum foil can allow you to control and isolate your heat almost like masking tape or a stencil can help you put paint where you want it and keep it away from where you don’t!
For example, when cooking a casserole, frequently you cover the top of your casserole with foil until your casserole boils around the edges (indicating that it is hot all the way through) Then you remove the foil to allow the radiant heat from your top heating element (or broiler) to brown the top of your casserole perfectly! This is an example of cooking in two phases (phase one is cooking from the bottom to bring your casserole to an even heat and then phase two is removing the protection of the aluminum foil to allow you finish the casserole by browning the top). More on this multi-phase cooking process is going to featured in another upcoming article.
Now how does all of this cooking information help you in a survival situation exactly?
So glad that you asked. The first and most obvious answer is that fully grasping these laws of thermal dynamics regarding heat and how to leverage them for better cooking in your home is that you can actually apply these same principles when cooking food during a crisis when you don’t have a microwave, oven or stovetop. Understanding the principles behind how your conventional home oven and stove top work… these same principles apply when using a grill, backpacking stove, fireplace solar oven or campfire!
But let’s take these principles several steps further! Understanding the principles behind how to harness heat to cook food can also be invaluable when it comes to how to keep yourself and your family warm!! That’s right… these same principles are still hard at work even when it’s cold outside and you need to safeguard your core body temperature.
This illustration of an ideal snow shelter shows how the
entrance of the shelter keeps heat in the shelter because
it is lower than the living area because heat rises and cold air
Let’s start with the fact that heat rises (convection). In a survival situation you can leverage this dynamic in many ways. One example of this would be creating a “bed” in your shelter that lifts you up and above the coldest air that falls to the floor of your shelter. A terrific example of this is when making a survival snow shelter. It is recommended that in your snow shelter you create a sort of “shelf” for you to bed on, and the area that is lower than your bed is where the cold air falls. This is referred to as a “cold air sink” and allows the coldest air to fall down below the level of your body keeping you warmer. There are many other examples of leveraging this principle in survival.
Next let’s look again at our three modes of heat energy transfer… again, this time from a survival perspective. Conduction is once again a very powerful and effective mode of heat energy transfer. We have several examples of conduction as a variable that must be considered when trying to stay warm. Our first example is simply getting wet. Most of us know that moisture is enemy #1 when it comes to hypothermia. But why? Well, because when water comes in direct contact with your skin, it sucks the heat right out of your body (the thermal energy in your warm body and the cold water are trying to find that thermal equilibrium attempting to make the water warmer and your body colder). That’s conduction at work, my friends. Your skin is making direct contact with that moisture and the moisture is sucking the heat right out of you bringing down your core temperature. This is why it is critical to stay dry in a survival situation or if you get wet to immediately find a way to get dry again.
Sleeping in a hammock allows you to sleep
much cooler than sleeping in a tent thanks
to convection. See the Pinterest pin source for
Another example of conduction in a survival situation is sleeping directly on the ground. Even if you are sleeping in a sleeping bag but doing so right on the cold damp ground, the ground can and will suck the heat right out of you if you do not have a protective insulating or reflective barrier like a foam or reflective sleeping pad or other barrier.
Now the two examples that I have given you tend to make conduction sound like the enemy in a survival situation. Such is not always the case. You see, in a situation where your core body temperature has become elevated (hyperthermia), you can quickly cool down your core temperature by taking a dunk in a cool stream! You can also drink warm liquids like hot beverages or warm a bottle of water or even rocks to put in your sleeping bag to help raise your core body temperature via conduction! This is why it is helpful to understand how heat works and how to harness it.
Radiation is once again less efficient than conduction, but the principles of radiation apply in a survival situation in a fairly effective and straightforward manner as well. Any time you have warmed yourself next to a roaring campfire you have benefitted from radiating heat. Any time you have used an electric or fuel powered compact heater of any kind you have leveraged radiant heat. Using a mylar space blanket in the back of your shelter to reflect (once again, just like visible light) campfire light/heat down and onto your bed is utilizing radiant heat to keep warm! You can use this same principle to protect yourself from too much radiant heat as well! Placing a reflective mylar space blanket over your shelter to reflect sunlight away from it can actually help keep you cool! Utilizing a reflective windshield panel as a sleeping pad can reflect the cold from the ground away from your body and your body heat back toward you!
A DIY ceramic pot room heater uses just the convection of
heat from a small tea light candle to warm a room.
While convection is utilized a bit less effectively in cooking than conduction and radiation, convection is actually a very significant variable in survival. The best example of this would be… wind (which is actually at least partially caused by thermal transfer and thermal equilibrium itself). You can have a terrific shelter and a terrific fire but if neither is protected from the cold wind it won’t matter much. That wind will suck the heat right out of you! Everything from the kinds of clothing that you are wearing to the location of your shelter to which side of your shelter you locate your entrance can be used to combat heat loss via convection.
On the flip side, convection can also be utilized to keep you cool in hot conditions. Examples of this would include utilizing a fan to help cool you (and assist with sweat evaporation… the body’s natural air conditioning) to hanging up off the ground in a hammock instead of on the ground in a tent to help keep you cooler!
One last variable to consider here: Again… heat, like visible light, is part of the electromagnetic spectrum. This means that heat, much like light, can actually be reflected. We explained this in a bit more detail above, but now just replace that reflective aluminum foil that you used while cooking with a reflective survival blanket or even a black surface (black absorbs light) and… voila! To learn more about the significance of heat being part of the electromagnetic spectrum, visit our Campfire Electricity page to learn more about generating electricity after dark using a campfire and a solar panel!
|How a sleeping bag uses insulation to maintain your core
body temperature. See the Pinterest pin source for this
Now there’s one dynamic in a survival equation that is a little bit different than what we see in cooking: unlike cooking, in a survival situation YOU are your primary source of heat. Your body creates it’s own heat by burning calories and circulating your blood. You can absolutely supplement your body’s innate internal heat source with external heat sources like a heater or fire to help you keep warm, but you can also just retain your body’s default core temperature (combat hypothermia) by taking prudent steps just to safeguard your body’s natural core temperature from environmental variables that threat it. You can do this in a number of ways like combating convection with wind proof clothing or shelter or utilizing reflective materials like a mylar space blanket or reflective fabric (just like letting that delicious prime rib rest on the stove top wrapped in aluminum foil so those delicious juices relax and stay in your meat where you want them)… or you can tap into yet another cool tool that we haven’t mentioned yet known as INSULATION.
Insulation is awesome. It’s so simple yet oh so effective. Insulation is simply the reduction of thermal transfer and is typically achieved using a barrier of some sort. This barrier can be comprised of a number of various materials that are not conducive to heat transfer or… simply just trapped air! Gases like air are very poor conductors (unlike solids and liquids) therefore are the opposite of conductors which means they are insulators!
Wonderbag cookers are amazing little “slow cookers” that
use extremely effective insulation to cook your food slowly
with no electricity! See the Pinterest pin source for this image
Coolers are great examples of insulators that keep your cold drinks cold even on a hot day. Ever seen one of those really cool non-electric Wonderbag cookers? These are another great example of insulation used to cook like a Crock Pot without electricity simply by trapping the existing heat inside your cookware.
A thermos or double-walled bottle (with the trapped air between the two walls) is another terrific example of trapped air style insulation. So are double-paned windows in your home. Your down comforter, coat or sleeping bag are also designed to trap tiny pockets of air all around your body with the loft of the fluffy down to keep your body warm. Furs work the same way!
Insulation can keep a body warm or cool depending upon the circumstances and how you use them. If you leverage a good understanding of the principles behind insulation, it’s amazing the almost limitless potential this knowledge can bring to you in a survival situation!
Can you think of any more examples of these principles of thermal dynamics and how they apply to cooking and/or survival? What are some tips or tricks that you plan to leverage in a survival situation? Let us know with your comments below!