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Thermacell Proflex on Vinson Massif, Antarctica

Proflex remote controlled, heated insoles help internationally certified mountain guide, Linden Mallory, and Penn Newhard combat Antarctic cold and top out on Vinson Massif.

Guest blog by Linden Mallory:

I wake up with the feeling I’m fighting spindrift as a shower of ice crystals hits my eye lids. The condensation from three sets of lungs breathing at rest throughout the night led to a layer of beautiful ice crystals lining the inside of the tent, detaching at the slightest movement of the nylon. We’re camped at 9,500’ on the Branscomb Glacier on the Vinson Massif, Antarcitca’s highest peak. Temperatures over the past few days ranged from -20 to -30F and this morning feels to be no different - it’s cold, Antarctic cold.

Penn Newhard climbing on Vinson Massif. Photo by Linden Mallory

I slide a hand into the chest pocket of the down belay jacket I’m wearing inside my -40F degree rated sleeping bag and hit the high button on Thermacell remote, then burrow back down into the sleeping bag for a few more minutes of warmth and rest. After a few minutes I can’t put off the inevitable any longer - it’s time to get up and get moving. I pull out my boot liners from deep in my sleeping bag and take the shells of touring boots from beneath my make shift pillow. My shells are still frozen solid despite my best efforts at keeping them warm throughout the night. I battle to coax the liners into the stiff plastic shells and then slide my feet in and don more layers of down before crawling out of the tent to fire up the stove and get ready for the day.

Moments like these were the true beauty of the Thermacell insoles for me: I'm used to my toes getting dangerously cold during the early morning hours at camp when I’m not moving consistently enough to generate enough heat internally nor is my metabolism humming enough to fight the cold early morning temperatures. My feet stay warm enough for the first few minutes but soon the frigid temps seep through the thin plastic of my touring boots and my toes start to lose their circulation until I’m forced to stop what I’m doing to swing my feet back and forth to break the shunting. Instead the Thermacell insoles kept my toes comfortably warm. The temperature regulation never made them obviously hot, but instead kept them right at a comfortable temperature so that I felt like my toes were Goldilocks warm - just about right.

While the true benefit was obviously the ability to keep my feet warm, I was surprised at how functional the remote proved to be. I fell into the habit of switching on the liners first thing in the morning while breaking camp and then turning them off 5-10 minutes out of camp when I was comfortably generating enough heat from climbing. The remote also gave me the flexibility to switch them back on on the fly to combat big changes in temps while climbing - when the winds picked up and the temps plummeted it was a simple as hitting a button on the remote in my pocket to keep my feet warm and I didn’t have to battle with sliding my overboots on or adding another pant layer as a stop gap measure for my feet.

My Thermacells insoles proved their place in my ski mountaineering kit, especially for long midwinter tours and big mountain expeditions. They aren't replacing a major piece of equipment such as warm liners or overboots but instead are a perfect supplement - the insoles give me a vastly greater degree of flexibility with managing cold temperatures. The thin design is comfortable to climb in all day long and doesn't affect the performance of my boots in ski mode by any noticeable measure. The remote makes them incredibly easy to use, a feature that far easier to appreciate when out in the mountains fumbling with numbing fingers on a windy ridge. I solved the potential problem of battery life, a big concern when I first picked them up, by carrying a set of backup batteries and occasionally topping them off using a solar panel when back in camp.

Returning from Antarctica, I unpacked by bags and after a few loads of laundry, stowed away much of the gear I won’t use until my next big expedition. But my Thermacells aren’t packed away with my down suit or my extra glacier glasses - they are sitting right on the shelf next to my touring boots, ready to grab for the next tour when the mercury drops.

 - Linden Mallory


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