Alexi Horowitz-Ghazi

But when World War II arrived, it presented a new kind of problem for the people in charge of outfitting U.S.

soldiers, one that called for a more technological approach.

This was a global conflict where millions of American soldiers would be potentially deployed to fight in all kinds of different climates and terrains, ranging from the balmy summers of the Pacific Rim to the frigid winters of Western Europe.

And one of the people tasked with solving this problem was a Harvard business professor by the name of George Dorio.

But for the purposes of our story, what's important is that George Dorio worked with a part of the military known as the United States Quartermaster Corps.

George Dorio took it upon himself to help organize a scientific effort within the Quartermaster Corps to solve this new gear problem the military was facing, employing many of the testing techniques that had emerged in places like the physiology department at Harvard.

At one point, the Quartermaster Corps designs a copper mannequin they can use to test out how cold or wet the soldiers might get when subjected to different kinds of conditions.

They named the mannequin Chauncey.

The model of the mannequin's name was Chauncey.

They had a team of Chaunceys, but they all had like copper skin that could tell how cold they were getting in different jackets.

After months of subjecting Chauncey and others to this terrifying testing regimen, the quartermaster engineers realize there may not actually be just one jacket to rule them all.

Now, people have obviously been layering in some form or another since the Paleolithic era.

When somebody threw a woolly mammoth poncho over their saber-toothed tiger skin.

But Avery says this is the first time layering for field performance was turned into a whole system.

A system built around a sort of simple olive green jacket.

But in 1943, this M43 jacket represented the cutting edge of clothing technology, a modular system that could be transformed to fit almost any environment.

There was padding for cold weather, a Porca edition for rain and snow.

And the military now had something that could be easily adapted for battles from the tropics to the Alps.

Almost immediately, they got to work mass producing the M43 field jacket, along with literal tons of other outdoor gear.

all meant to keep millions of soldiers as fighting fit as possible for years into the future.