When Troy Carter was an infantryman with the Army’s 10th Mountain Division, he spent many hours standing in the heat of a concrete watchtower overlooking Bagram Airfield, Afghanistan. Beneath the blazing sun, Carter wore heavy body armor, a helmet, and a long-sleeved battle dress uniform, but the Army would not let him take off any of it.

“One time on guard duty I took my BDU top off, so I was just wearing my body armor and a t-shirt,” Carter recalled. “It was so hot, but this platoon sergeant came by and he was so mad at me.”

Countless other American service members have been in Carter’s situation over the past two decades of war in Afghanistan, Iraq, Syria and other countries where the summer heat is unbearable. But the Air Force may have a solution. 

An inventive security forces airman (the Air Force equivalent of military police) named 1st Lt. Justin O’Brien came up with a low-tech body armor cooling system that is meant to keep service members cool. The simple system consists of a water bladder (like the CamelBaks troops already carry to drink from), a battery-powered pump; and a series of tubes, valves and pads connecting the two together.

Air Force officer invents low-tech body armor cooling system to help you chill out
Components and fluid flow are shown in a patent illustration of the Liquid Cooled Plate Carrier (Air Force illustration / Tech Link)

The pump draws water from the bladder into pads beneath the body armor on the wearer’s chest, back, sides, waist, neck, and or head. As the water warms up, the wearer can drink it without drawing cool water from the bladder. The device can also be worn in a backpack, or as a standalone vest.

O’Brien first pitched his idea during the Air Force 2020 Spark Tank competition, the service’s annual contest where airmen present innovative technologies and ideas to the Air Force Materiel Command. The Air Force then works with the private sector to develop and produce those inventions, if they win the contest.

“Heat stress and related illness negatively impact all aspects of the military; both in an operational setting and in training,” O’Brien said in a press release when the liquid cooled plate carrier was a finalist in Spark Tank. “The LCPC active cooling system is a device that keeps our airmen in prime fighting condition, while keeping heat stress at bay.”

Air Force officer invents low-tech body armor cooling system to help you chill out
Air Force 1st Lt. Justin O’Brien breaks down his invention, the Liquid Cooled Plate Carrier, in a 2019 video. (Air Force courtesy video)

Now, the Air Force seems to be going full-steam ahead with the project. The Air Force has a patent pending for LCPC with the U.S. Patent Office, and the branch is looking for a business or entrepreneur to develop and commercialize the technology through a license agreement with the Air Force.

“I think anybody who has worn body armor in the heat would be interested,” in the LCPC, said Carter, who is now the editor of Tech Link, where the Air Force posted an advertisement for the license agreement.

Carter praised O’Brien for designing such a simple system. For example, the pump is a modified mini aquarium fish tank motor, Carter said. Service members already carry CamelBaks to stay hydrated, so they don’t need to carry an additional water reservoir to stay cool. In a 2019 video explaining the LCPC, O’Brien said the system adds only 10 oz of weight to the wearer’s load. But if that’s too much to wear out on patrol, it would at least be useful for military police pulling gate duty, or for grunts stuck in a guard tower like Carter once was.

“He’s being inventive to cool off the Joes,” he said. “He really thought it out.”

Air Force officer invents low-tech body armor cooling system to help you chill out
Airmen test out the LCPC while doing PT in 2019 (Air Force courtesy video)

In the 2019 video, O’Brien tested out the system by having four airmen wear it while performing a fitness test for ten minutes. The airmen monitored their heart rate and temperature throughout the test, the officer explained. During the workout, the temperature inside the vest rose up to 21 degrees higher than the ambient temperature, he said. Then at the end of the workout, the airmen turned on the LCPC. The results were instantaneous, O’Brien said.

“It’s like I jumped in an ice bath,” said one airman in the video.

Within 30 seconds, temperatures inside the vest dropped 21 degrees on average, O’Brien explained. Within two minutes, they dropped an average of 32 degrees.

“It feels like an iceberg’s right on my back,” said another airman, hands on knees after the workout.

“Ah that feels nice,” said a third.

This isn’t the first time the military has tried to make wearable devices to keep troops cool. In fact, in 2005, the U.S. Army made vests that worked like portable air conditioners, according to Tech Link.

The suits contained over 110 feet of tubing that contained a 65-degree liquid which could remove heat from the body. But the suit never became operational, and researchers were still testing them out in 2014, according to an Army press release.

Carter said he was not aware of any plans by the Air Force to make the LCPC standard-issue, but it would sure be a cool idea, even as U.S. troops leave Afghanistan. Top military leaders are most worried now about a war with China, and at press time it was 84 degrees Fahrenheit with 89% humidity at 3 o’clock in the morning in Taiwan, the island off China’s coast where that war might start.

“We seriously need to get this vest to the rest of our guys,” said an airman at the end of O’Brien’s video.