How to stay warm while sleeping during winter camping.
I considered methods that would minimize costs, as well as methods to sleep warmly regardless of cost.
Bedding + blanket (+ hot water bottle or futon dryer)
This method involves bringing your home bedding to the campsite. Add a winter blanket to keep you warm.
Even so, I don't like the cold when I get into bed, so I warm the futon with a hot water bottle.
If you can access an AC power source at your campsite, using a futon dryer is also an effective option.
If you switch it on a little before going to bed, you'll have a fluffy and warm futon ready to go.
Sleeping bag + air mattress (+ hot water bottle)
This method involves placing an air mattress under a winter sleeping bag.
Air mattresses offer superior insulation compared to other types of mattresses, effectively blocking out the cold from the ground.
Using a hot water bottle in conjunction with it will further increase the warmth!
Sleeping bag + cot (+ hot water bottle)
I slept using a cot in my sleeping bag.
A cot, which is physically elevated from the ground, offers not only a more comfortable sleeping experience but also better insulation.
By placing a blanket between the cot and sleeping bag and letting it hang down to the bottom of the cot, air movement underneath the cot is suppressed, the air warms up, and you can sleep more comfortably.
Add a hot water bottle to that and you're unstoppable.
Futon + Kotatsu
Finally, it's time for our family heirloom, the kotatsu (heated table).
Assuming you have access to an AC power source, combining a futon and a kotatsu (heated table) makes for a very warm setup.
It's pretty much the living room at my parents' house.
To avoid burns, I'll turn it off once it's warmed up.
How to bring a kotatsu (heated table) to a winter camping trip and how to use a heated carpet.
Going on a winter camping trip and enjoying some relaxing time around a campfire is great, but how about enjoying some tangerines under a heated table (kotatsu) outdoors?
Adopting the currently popular low-style design makes implementation surprisingly easy.
Making an impromptu kotatsu using a low table
Approximate size for the number of people using a low table.
Height cm Width cm Depth cm
1~2 people 80~120 50 30~35
4 people 120 80 30~35
5 or more people 150 80 30~35
Place a blanket over a low table and put two hot water bottles inside, and voilà, it's warm! You've got an instant kotatsu (heated table).
For low tables, a good size guideline is 80-120cm x 50cm for 1-2 people, 120cm x 80cm for a family of 4, and 150cm x 80cm for 5 or more people.
One hot water bottle isn't enough to warm the entire table, but three will raise the temperature, though they take up too much space.
If 3-4 people put their feet in, it gets in the way, and there's a risk of low-temperature burns if their feet touch the hot water bottle, so 2 is the appropriate number.
Placing a napped rug underneath will make it even warmer. This is because a larger amount of air trapped inside provides more warmth.
Choose a rug that is larger than the coffee table, and one that is large enough for you to comfortably sit on.
Place a blue tarp or picnic sheet under the rug.
Not only does it prevent rugs from getting dirty, but even a thin rug makes a difference in how cold the floor feels.
Use a heated carpet or heater
Placing a heated carpet under the makeshift kotatsu (heated table) mentioned earlier will increase the warmth. If your campsite has AC power, be sure to use it.
The power output at campsites is usually between 700W and 1000W.
Most heated carpets designed for a 2-tatami mat area have an output of around 500W, so they should be perfectly usable.
However, portable power supplies typically have an output of 400W (even the best ones are only 700W), so using them would be difficult.
Furthermore, portable power supplies are not practical in low-temperature environments because they cannot perform adequately in such conditions.
Another method is to use the warm air from a fan heater to create a heated table (kotatsu).
The approximate size of a fan heater for winter camping is suitable for a wooden house (7 tatami mats) or a concrete house (9 tatami mats).
A tank capacity of around 3.5 liters would be ideal.
This size is perfect because it keeps the inside of the tent warm enough without taking up too much space.
Furthermore, even during ignition, when the load is highest, the power consumption is only around 400W, and at powered campsites, it is often possible to use it in conjunction with the aforementioned heated carpet (around 500W).
Attach a thick, bellows-like object to the hot air outlet and pull it into the heated table (kotatsu).
This product is designed to direct the warm air from a fan heater, not to heat the entire room, but to warm a specific spot.
Because the warmth from the heater is directly absorbed, it's even warmer than a "hot water bottle kotatsu."
Do not go inside a kerosene fan heater, as there is a risk of carbon monoxide poisoning.
*The use of heating appliances in closed rooms is prohibited. When using them, be sure to ventilate the room well and use a carbon monoxide detector.
The warm air from a ceramic fan heater is insufficient for heating, making it difficult to warm a room adequately, and using it in conjunction with a heated carpet may result in excessive power consumption.
