As the sun rose on a recent morning over the 25th Infantry Division’s Lightning Academy — the Army’s jungle warfare school in Wahiawa — a group of medics was being trained in battlefield first aid.

A member of the Army’s 3rd Special Forces Group out of Fort Bragg, N.C., who was evaluating the soldiers, told them, “This is medical training, but remember, you are combat medics.”

As they approached a “patient,” an explosion rang out and gunshots popped. Once the soldiers secured the area, they began applying first aid, working to stop the bleeding. But unlike usual training exercises, real blood was coming out of the patient — a human cadaver that had been pumped with cow blood and inflicted with real injuries.

The weeklong training event was overseen by the 325th Brigade Support Battalion of the Oahu-based 25th Infantry Division’s 3rd Infantry Brigade Combat Team. It was the second iteration of a new program developed by soldiers in Hawaii and first carried out in January 2022.

“We kind of saw the need for specific training for the medics in the jungle (area of operations),” 1st Lt. James Barr, one of the soldiers who helped create the program, told a Honolulu Star-Advertiser reporter who observed the training Jan. 25.

Combat medicine training in the field with cadavers isn’t new for the U.S. military, but historically it has been reserved for Green Berets, Navy SEALs and other elite special operations troops. Medics from Army special operations units flew in to Oahu to evaluate the trainees and give them advice on how to better render first aid, move and ultimately save their patients.

Exercise planners said the training in Hawaii was unique in being organized and mostly carried out by conventional troops and is one of the largest-scale exercises that Safeguard Medical, a North Carolina-based company that provides cadavers, has worked on.

The company, which provides a range of services to first responders and military clients, shipped 10 cadavers to Oahu for the exercise.

Troops from around Oahu, including personnel from Tripler Army Medical Center and Navy corpsmen, went through the course — a rare opportunity for this sort of realistic training. Usually, they train with mannequins, but Sgt. 1st Class Bryan Essig, a senior medic who treated combat casualties in Afghanistan, said giving medics training with real human tissue is a “game changer” that will both prepare them for the shock of actually handling a body and help them better save lives in the real world.

Groups of soldiers were tasked with maneuvering through the jungle to find the cadavers, which had a variety of wounds ranging from severe lacerations to missing limbs. After providing aid, troops then moved their simulated patients to an evacuation point where either a medical evacuation helicopter or a military ground ambulance would retrieve the casualties.

The cadavers were then brought to a grassy clearing where a series of tents and vehicles made up a field hospital where surgeons and other medics worked, themselves training on the cadavers to hone their skills.

Essig said that when he was sent to Afghanistan within nine months of getting assigned to his first unit, “I did not have the luxury to train like this.”

“Mannequin technology is much better now than it was 15 years ago, where we can actually pump them up and perfuse fake blood through them,” he said. “But mannequin tissue does not react like human tissue does. It just doesn’t.”

According to Barr, Safeguard Medical’s TruBODIES Reanimated Tissue Training system provides “realistic, immediate feedback for the medics on the ground.”

One group of medics whose uniforms were caked with mud from moving, fighting and carrying a patient through the jungle said that working with cadavers was a huge change of pace from what they would usually experience during field training.

“It’s definitely interesting feeling what it’s like to stop the bleeding in an actual human being,” said Pfc. Chris Berns. “You’re actually putting in gauze into the human body instead of just in a hole in a mannequin. You’re actually seeing how a tourniquet will force the body to stop bleeding.”

Spc. Kendra Moore described moving through the jungle carrying a cadaver in the early morning as the dew was still thick, making the ground slippery with fresh mud. Sgt. Fafundo Zalazar said that just carrying a human cadaver was different from the mannequin they would usually carry on a stretcher for evacuation.

“It was more lopsided, I would say,” Zalazar said. “You definitely felt the weight shift (compared with) a mannequin where it’s pretty balanced out. Even if it’s missing one of his legs, it’s pretty balanced out. So the weight shift is tremendously different.”

For the 325th Brigade Support Battalion, the jungle exercise was a return to its roots after two decades of deploying to the mountains and deserts of Iraq and Afghanistan. The unit was activated at Schofield Barracks shortly after the Japanese navy’s Dec. 7, 1941, attack on Oahu, and by 1942 it was setting up field hospitals in the jungles of the Solomon Islands.

“We’re doing the exact same thing we started doing in 1941,” said battalion commander Lt. Col. Brandon Grooms.

As counterinsurgency fights in places like Iraq and Afghanistan dragged on and casualties mounted over the past two decades, the military tried various ways to give its medics the more realistic trauma care training. In 2008, PETA protested when the 25th Infantry Division decided to use live pigs to train combat medics in preparation for a deployment to Iraq.

The Pentagon ultimately invested in heavily armored vehicles to protect troops from ambushes and the improvised explosive devices favored by insurgents, and there was an established procedure to get badly wounded troops off the battlefield as quickly as possible within “the golden hour” in which they would be more likely to survive.

But military commanders are moving away from counterinsurgency warfare to preparing for the potential of larger conventional battles as geopolitical tensions boil.

The Pentagon has gradually shifted its attention to the Pacific, which it considers its top priority theater of operations, amid tensions with China. Oahu is the nerve center for U.S. military operations in the region, which are overseen by U.S. Indo-Pacific Command at Camp Smith.

In a potential conflict with Chinese or Russian forces, which have more weapons to shoot down enemy aircraft than the insurgent groups the U.S. military has been accustomed to fighting, American troops may not be able to count on aircraft being able to assist the way they have in the past. The bloody fighting in Ukraine has offered a sobering look at what that could look like as heavy weapons tear through armor, artillery rains down on populated cities and anti-aircraft weapons blow helicopters out of the sky.

“I was spoiled,” said Essig, explaining that he used to count on helicopters to swoop in and retrieve casualties in Afghanistan after medics rendered first aid. The emphasis of the recent training was on providing “prolonged care” in the field to keep casualties alive until safe evacuation is possible.

“That’s where the key is going to be,” Essig said. “That’s where medicine is moving in a combat environment.”

Military leaders are also thinking about scenarios where casualties could be much higher in a large- scale conflict between superpowers.

Grooms said mass casualties weren’t the focus of the recent Oahu exercise and that cadavers were used to give medics quality, individual training on human anatomy for saving lives. But the possibility of military medical personnel having to deal with hundreds of wounded during a battle is on the minds of those who might one day shoulder that burden.

Barr said, “It’s going to change the dynamic of how we need to triage, and I think that’s still in refinement. I don’t know personally how it’s really going to look.”

In the wars in Iraq and Afghanistan, the most badly wounded were prioritized to increase their chance of survival. But Barr said that in any future large-scale battles, medical personnel may have to prioritize the ones who are most likely to be saved and able to be returned to duty.

“Decisions like that are going to be made well above my level,” Barr said. “Down at the company level, we’re just here to execute (and) save as many lives and keep that fighting force as fit to fight as we can.”