Hardening the Body for Winter Weather

We have reached that time of the winter when 40°F seems almost springlike. Even 26°F isn’t bad, which is what I told my wife when I came inside for lunch on Friday. My body has adapted, or “hardened” as some would say, to where it doesn’t feel the cold until around 22°F. And if it’s sunny with no wind, even that can feel comfortable.

This hardening is technically known as “seasonal acclimatization,” and it is a real phenomenon that involves your vascular system and your thermoreceptors. This explains how a guy working in Alaska can manage just fine at -40°F while his dad in Florida puts on a sweater when it hits 62°F. It also reminds me of a UPS man we used to have who wore shorts all year, regardless of the weather.

In the summer, your body adapts the other way around. People with outdoor jobs that subject them to summer heat—like roofers and road crews—lose less salt through sweat and their heart rates slow.

Because I spend an average of 90 minutes or more outdoors every day, my body has acclimatized to the winter. I’m sure sleeping in a bedroom that is often in the low sixties also helps.

If your HVAC is set at 75°F, your car is in an attached garage, and the only time you are exposed to the weather is when you dash from your parked car into a store or restaurant, then you aren’t acclimatized. This will make it hard for you if your heat source goes out or you are in a survival situation.

Hardening Your Body

Whether you attribute this adaptation to Mother Nature or to an evolutionary process, it’s a good thing for preppers, soldiers, farmers and anyone working outdoors. It’s also a good reason to spend time outside in any weather.

If you need to harden your body to the cold or adapt to the summer heat, the recommendation is to start with only 20 percent of your normal workload, then increase gradually to give your system time to adjust. Keep this in mind if you are forced to bug out on foot during extreme heat or cold with people who are not used to the weather.

Allow at least two weeks for your body to adapt to summer heat.

Phase	Timeline	What is Happening in Your Body
Phase 1: Early	Days 1–5	Heart Rate Stabilization. Your body expands its plasma volume so your heart doesn’t have to work as hard. You feel better, but your core temperature still spikes dangerously fast.
Phase 2: Middle	Days 6–10	Sweat Optimization. You start sweating earlier and in greater volume. Your body begins the process of salt conservation (reclaiming sodium from your sweat).
Phase 3: Completion	Days 10–14	Thermal Maturity. Your core temperature remains stable even under heavy load. Your metabolic efficiency is at its peak.

If you work outdoors, your body adjusts automatically during the seasonal changes, but this is a good warning not to overdo it on the first hot day of the year. It also explains why you might need to wear a knit cap during the first cold snap, but you manage fine without it a few weeks later.

Firewood Heats you Two or Three Times

Besides the daily dog walks one frequent outdoor activity is working with firewood: cutting, splitting, stacking, or hauling it around. On Friday—the day between two polar vortexes—I carried 63 pieces inside for my stove and more than 30 for the fireplace insert upstairs. Many of the latter I split with an axe because the insert requires smaller pieces.

We continue to consume firewood at what feels like a record pace, and this is our sixth winter in this house. We’ve consumed more than 30 feet of double-firewood stacks four to five feet high. That’s 360 cubic feet of firewood, just about three cords. That’s about half of our firewood, but two unburnt cords are tulip poplar, which doesn’t burn as well or make as good coals as oak, locust, maple, or cherry. I can put a few pieces of oak in the stove when I go to bed, and there will still be coals when I wake up. With tulip poplar, we’re lucky if there are coals left two hours later. It makes heat, and it will keep us warm, but we’ll be checking the fire far more often. Plus, those two cords will be consumed faster than our normal firewood.

I have one emergency cord that is not as seasoned as long as I would like, but I expect we’ll have to burn it before spring arrives.

Landslide Prevention

Our landslide prevention plans took a giant leap forward this month. The contractor came out and dug a massive gully to intercept and redirect the water that had been rushing down the mountain and causing continued erosion in the landslide left behind by Hurricane Helene. He also dug out six to eight inches of newly deposited dirt from the same area at the bottom of what they tell us is called “a debris slide.” This is where we had to dig out three or four feet of dirt and rocks after the storm. We also installed a silt fence to help eliminate this kind of spillover.

The other end of the mountain slope above the house did not have a debris slide. I attribute this to the old logging road climbing up it at a diagonal. I believe the road intercepted and steered the water down the hill in a safer manner, preventing a slide. The new gully is supposed to achieve that for us on the bad side of the mountain. (I’d include a photo, but it’s snowing and you can’t see much.)

We hope this new effort to redirect the water will prevent a debris slide from recurring. If not, it should minimize it, and the “landslide containment fence” of pallets I built by driving T-posts a foot or more into the ground will help protect the house.

After having heavy equipment going back and forth, we’ll need to plant grass again this spring. I’m thinking of just going with white clover. The bees like it, it grows just fine, I can plant it in the winter, we don’t need to water it, and clover needs little or no mowing. Lawns are overrated.

More Firewood Poles

The contractor went above-and-beyond the call of duty by stacking a nice pile of maple and other hardwood logs near my log splitter. These were from trees he had to clear. Most of them were already down as that section was one of many windward slope blowdowns. The combination of tropical-storm-force winds being squeezed up through mountain valleys either snapped the pine trees in half or tipped over the broadleaf trees, many of which were easy victims because of the saturated soils. The days of rain leading up to Helene had turned the ground to soup. This not only made it easy to knock over trees, it contributed to the mudslides and debris slides like we experienced.

I told the contractor to leave the tulip poplars and other trees that don’t make good firewood up there to rot. (If the SHTF tomorrow, we can always go up there and cut them up to burn in a cook stove.) He brought down loads of limbs and brush, which made up a large burn pile. We took advantage of a snowy day to burn it without endangering the surrounding forest. That fire burned for at least 18 hours.

This job is more proof of why people who own rural property often need a mini excavator. If I had one and were a skilled operator, I expect it would have paid for itself by now.

Solar Power Report

As expected, we didn’t make much solar power last month. Surprisingly, we still have a negative power bill. Our electric bill was for 620 kilowatt hours (kWh) while our solar panels produced about 440 kWh, 120 less than we produced for the same period in 2024. December was so cloudy, we consumed in just that month a third of all the grid power we used in the entire year.

Last year, we purchased more power in January than in December; it will be interesting to see if that is the case again. So far, I think it has been sunnier this month. When I checked the app on a sunny day this week, we were producing 7.4 kWh, which is close to our maximum output.

In 2025, we actually produced more power than we used by about 400 kWh. I assume this is why our power bill is still below zero. Sadly, our production and our use do not align perfectly on a daily or monthly basis, which is why we remain attached to the grid. But should the grid go down, we will be in better shape than most.

LiFePO4 Battery Limitations

One thing I learned last week is that our batteries are limited in how quickly they can recharge during cold weather. When the temperature in our garage, where the batteries are mounted, falls below 50°F, the system throttles the rate at which they recharge. It was on that day when we were producing 7.4 kWh of power that I noticed the batteries were only accepting a total of 3.3 kWh. The extra power was being sent to the grid.

Normally, our batteries can be charged at 10 kWh. Thinking a setting was wrong, I called the manufacturer.

They explained that the colder it is, the slower they charge the batteries. This isn’t particular to my batteries, but to all lithium iron phosphate batteries. The reduced charging rate is designed to protect the batteries. My batteries have built-in heaters, but that just keeps them from freezing; it isn’t designed to keep them operating as if it were summer.

I also learned that if the temperature falls to -4°F, the batteries shut down. If the temperature in my attached garage ever drops that low, I expect the batteries will be the least of our problems.

During the sales process, no one warned us about this cold-weather problem. It’s a good argument for why you don’t want your battery stack to be outdoors, even if it is in a waterproof cabinet. Let this be a warning to anyone building an off-grid system or installing LiFePO4 batteries in cold climes.