In cold climates or as needed, knowing how to make a firebed can be a life saving survival skill. A firebed uses embers buried under several inches of dirt to warm the ground under you, helping you stay warm even in freezing temperatures. In a survival situation, you’ll need to plan ahead of time and allow a couple of hours to construct and test the firebed before using it. This means that if you know you’ll be sleeping outside you’ll want to gather the necessary resources and select an ideal site several hours before darkness if at all possible. Start with selecting the site of the firebed before anything else to prevent wasting time and energy.
An ideal site should be a level area preferably already providing some sort of protection from the elements such as a rock overhang or forest canopy. Avoid ground that contains rocks, thick roots, or water below the ground surface. The actual firebed you’ll dig will be approximately 1ft deep, 1-2ft wide and a few inches longer than your height.
Also consider a site near fuel source as you’ll need to gather both kindling and tinder like insulation if available in your location. Hardwoods such as white ash, American beech, Big leaf Maple, etc., are preferred over softwoods if available.
Required Materials & Construction
After the site is selected it’s time to gather the kindling and insulation and actually dig the firebed. You’ll need to gather a supply of kindling and fuel before you begin to construct the firebed. The actual wood you use will produce the coals needed to sustain the warmth the firebed will produce throughout the cold night.
Once the fuel has been gathered, you’ll also need to collect enough natural insulation to cover yourself with. This will act as an insulator to trap the heat as well as make the firebed more comfortable to sleep on. You’ll need as much insulation as you can gather. Some examples of natural insulation are leaves, grass, pine needles, etc. Ideally, there will be enough insulation to cover the firebed with a thick layer with enough left over to cover the survivor for extra warmth and comfort.
Finally, locate stones about the size of an orange that will later be used to line the inside of the trench to help enhance air circulation.
With the materials gathered it’s time to dig the firebed. If it’s snowy or all the ground near you is frozen, you may need to thaw the ground by simply building a fire on top of it. Once the ground has thawed you can build the firebed. As mentioned above, you’ll want to make the bed approximately 1ft deep and wide enough to accommodate your body. The bed will need to be long enough to comfortably lay in.
At this stage, line the trench with the stones you’ve gathered. Ideally, you’ll want to space them approximately 1”-2” apart but if you can’t locate that many, you can spread them farther apart. The rocks are just an enhancement, if you have them they’ll help the air circulate which will help the fire burn more intensity and produce a greater number of coals. Remember to avoid porous or wet rocks in or around any kind of fire, including the firebed, as they may explode when heated. With the rocks in place (or if there are no rocks available and this step is skipped), it’s time to start the fire.
Starting the Firebed
With the firebed dug and fuel sources gathered, it’s time to start the fire that will later produce the coals needed to heat the firebed throughout the night. In the trench you just dug, start a fire using the kindling and fuel sources gathered earlier. The end goal of this fire is to spread it as evenly as possible throughout the entire trench. As the fire burns down, hot coals will be produced which will be used to heat the firebed you’ll be sleeping on later.
It’ll take approximately 2-3 hours to allow the fire to burn down to produce a sufficient amount of coals. The more coals the hotter the firebed will be and the longer it’ll last. Adapt to your surroundings when deciding how hot you think you’ll need the firebed to be to keep you comfortably warm. Also, keep in mind how you’re dressed.
After the desired amount of coals have been produced, spread them as evenly as you can around the trench. Then bury them with approximately 4” of the dirt you dug out to form the trench. Once the dirt has been thrown on top of the firebed, tamp it down using whatever available resources you have. When you have thoroughly covered and stamped down the firebed, visually inspect as well as use your sens e of touch to look/feel for any smoke/steam or excess heat sneaking through the dirt.
The next step is to simply wait for the dirt to become heated. Depending on the size of the firebed and the amount/intensity of the coals this may take some time (1 or more hours). The general rule of thumb is if the firebed becomes heated before at least 1 hour, add a small amount of dirt on top and stamp down again. You can utilize this time to prepare the rest of your camp by making a reflector fire and boiling water, cooking, etc. You may also want to continue to gather dry insulating materials to ensure you have enough to last the night. The last thing you’ll want to do in the middle of a freezing night is get up and forge for more pine needles or grass because you’re still to cold to sleep.
It’s also recommended to use logs or improvise some type of additional wind barrier on either side of the firebed. You’ll know when the firebed is ready to sleep on when the dirt is comfortably warm to the touch.
The firebed can be constructed when planned properly and will help keep the survivor warm during a cold night. Although the preparation will require a moderate amount of time and energy, you can easily dig the dirt up and reuse the firebed more than once if you stay in the same location for a few nights. If there’s more than one person, you can adjust the firebed to accommodate however many bodies are with you. Although this obviously be more labor intensive, the added body heat will make the firebed even more heated than with just one person. A key metric by which to judge the firebed is how long it’ll provided warmth. You’ll want to practice this skill several times to get the hang of using the right mix of coals and dirt to produce a warm bed that will keep you properly heated throughout the entire night.