Grunt: The Curious Science of Humans at War

by Mary Roach

  “There was one patient standing in the middle of the room,” Cheech says. “Standing in the middle of the room. And no one paid any attention to him. You need to make your bubble bigger. Don’t get fuckin’ tunnel vision.”

  The technical term for fuckin’ tunnel vision is attentional narrowing. It’s another prehistorically helpful but now potentially disastrous feature of the survival stress response. One focuses on the threat to the exclusion of almost everything else. Bruce Siddle tells a story about a doctor who had some fun with an anxious intern. He sent him across the emergency room to sew up a car crash victim’s lacerations. The intern was so intent on his stitching that he failed to notice his patient was dead.

  IT IS easy to get lost on the way to the Strategic Operations bathroom, and very entertaining. You might pass a rack of freshly painted excretory systems hanging in the sun to dry, or a man seated at a workbench, trimming the seams of a molded silicone Cut Suit penis.§ You might overhear a person say to another person, “If you use different blood, it voids the warranty.” At one point I take a wrong turn and find myself in a storage area. A filing cabinet drawer is labeled “Spleens.” “Aortas,” another says. On the top of the cabinet, Cut Suit skins are folded like blankets. When I finally find the bathroom, the sign on the door, which uses the military slang “HEAD,” confuses me in a way it would ordinarily not have.

  Making my way back, I pass a Cut Suit training tutorial and decide to sit in. A woman with creamy tanned skin and variegated blonde hair stands at a table with the suit’s various components, which she is demonstrating, like Tupperware, to two Marines from Camp Pendleton. (The Marine Corps had just purchased one of the suits, and the two Marines, Ali and Michelle, were training to be Cut Suit Operators.) The teacher, Jenny, shows them how to unsnap the “visceral lining” to access the abdominal organs. “You can do an evisceration,” she says pleasantly, and notes that a slashed latex lining can be simply discarded and replaced.¶ Visceral Linings are available for purchase in packages of two hundred. It seems like a crazy amount of evisceration.

  Jenny picks up a loose intestine and tells Ali and Michelle that they could, if they wished, fill it with simulated feces that they could make themselves, using oatmeal dyed brown and scented with a party novelty called Liquid Ass. The Cut Suit training coordinator, Jaime de la Parra, used to travel to conferences with Liquid Ass in his luggage, for demonstrations. Other employees, including Jenny, do not, and recently Jaime asked her why. “I told him: ‘Because no one will come to our booth.’”

  Segall, the Cut Suit’s inventor, is proud of its realism, and justly so. Still, no matter how rank the intestines smell or how realistically the amputee’s stump is bleeding, students must know it’s not real. No one hacks off a limb to train a group of medics.

  Or not a human limb, anyway.

  AS FAR back as the 1960s, students of combat trauma medicine have practiced life-saving procedures on anesthetized pigs and goats. There would be no issue here, except for the fact that barnyard animals don’t naturally wind up in situations where they’re shot or stabbed or blown up by an IED. So the only way to train students on them is to hire a company to do the shooting or stabbing or leg-removing. There’s one of those companies not far from here.

  Live tissue training is the topic of conversation at lunch today, on the back deck of Stu Segall’s diner. Stu and I are joined by Kit Lavell, the company’s executive vice president. Lavell fills me in on legislation that would require the Department of Defense to reduce the number of animals used for live tissue training from the 2015 level—about eighty-five hundred per year—to somewhere between three and five thousand. An animal rights organization called Physicians Committee for Responsible Medicine is behind the push. Advances in patient simulators—and high-drama Cut Suit demos before members of Congress—have made it harder for defenders of live tissue training to make their case.

  Unfortunately for pigs, the layout and size of their viscera approximate ours, as do their blood pressure and the rate at which they bleed. Goats are better for practicing emergency airway procedures, as there’s not four inches of neck fat to slice through.

  I watched a YouTube clip purporting to be part of a live tissue training class that someone surreptitiously filmed. A group of men stand around a folding table on a rainy day. A makeshift roof with a tarp drips overhead. Two or three men at a time lean over an inert pig laid out on the table. Their backs are to the camera. They chat quietly. They look like pit masters at a whole-hog barbecue. A veterinarian is there, and you can hear someone ask him to give the animal a bump, meaning more anesthesia. The leg amputation happens off-camera, but you can see the instrument the instructor uses: a set of long-handled shears of the sort one might use to cut through chain link. It sounds ghastly but gets the job done quickly. Assuming the anesthetic was competently administered, the proceedings struck me as no more upsetting than what goes on in slaughterhouses every day in the name of bacon and chops and short rib ragu.

  For that very reason, Siddle feels, it’s an incomplete “stress inoculation.” “While it’s a good experience to work on something live, something that pumps, it’s not a human. It’s not screaming.” To gain experience with actual screaming humans, Camp Pendleton’s corpsman trainees may spend time observing and helping out in an emergency room in a gang-saturated Los Angeles neighborhood. “That’s our equivalent of Iraq or Afghanistan,” Ali said earlier. “Gunshots, strafings, stabbings.”

  Michelle, the other Cut Suit Operator-in training, experienced both live tissue training and a stint in an emergency room. She found them helpful in different ways. Live tissue training provides a controlled teaching environment. Students can try things out, grab a slippery artery between two fingers to stanch a bleed. “You’re not,” she said, “going to be doing that with a patient in an emergency room.”

  With its bleeding, wheezing, cursing role-players, Strategic Operations tries to be one-stop shopping: something pumping, human, and screaming. “It creates a willful suspension of disbelief,” says Stu, disarticulating a fried fish. I don’t quite understand that phrase, but I do understand what he says next. “We’ve had students wet themselves, soil themselves, vomit, faint.”

  Lavell shares that Dennis Kucinich lost his congressional lunch at a Cut Suit demo. The representative from Ohio was sitting in the front row with his wife, Elizabeth, the prominent DC vegan and animal rights advocate. “When the actor started screaming and the blood started spurting, Kucinich went white. You could see the reverse peristalsis beginning.” I glance at neighboring tables, half expecting to see some here. “His wife got up and helped him to the door.”

  THE MAIN stressor of combat medicine is absent from every training simulation. No one is shooting real bullets at or anywhere near you. “Training is limited by liability,” said Siddle. He sounded a little mournful.

  “The high number of returnees diagnosed with PTSD suggests we are not doing enough,” scolds Colonel Ricardo Love in his paper. Love hailed the ancient Spartans’ approach to “building psychological resilience in their forces.” Pelopidamus, looketh upon these novel strategies for building resilience. “On several occasions [the] war games were deadly and some boys were killed.” According to Sparta scholar Paul Cartledge, other military resilience-builders included the stalking and killing of random slaves and “the braving of whip-lashing seniors# in order to steal the largest possible number of cheeses from the altar of (Artemis) Ortheia, a goddess of vegetation and fertility.”

  Many years ago, reporting a story on killer bees, I experienced a kind of stress inoculation. I accompanied a team called out to remove a hive on a farmer’s land in south Texas. The venom of “killer” honeybees is the same as that of ordinary honeybees, but the bees are far more aggressive in their defense of the hive and their pursuit of interlopers. The larger the hive, the more defensive the bees. This hive filled a fifty-five-gallon oil drum. I wore a bee suit, but I hadn’t attached the veil properly and bees began getting
underneath it and stinging me. Later that day I and my throbbing welts visited a keeper of ordinary honeybees. While we talked, bees would light on my arm. My normal reaction would have entailed flailing and girly alarm noises. Instead I calmly watched them crawl around. Fear of bees: gone.

  But would it have worked in reverse? Would exposure to regular honeybees have inoculated me against the fear I felt inside the killer bee swarm? Caezar’s theatrics and Tom Hanks yelling and the hectoring instructors—these are regular honeybees. Still, as Siddle allows, “Anything that narrows the gap is good.”

  The other way to train medics is to have them practice a skill so many times that it becomes automatic. So when the prefrontal cortex goes AWOL, when reasoning drops away, muscle memory, one hopes, will persist. Do it enough times, and you can administer first aid in the ultimate survival stress scenario: when the gore is your own. Recall the combat engineer from chapter 4 who’d stepped on an IED. “Without thinking”—as he aptly put it—he pulled out a tourniquet and placed it perfectly on what remained of one leg.

  CAN THE carnage of an explosion ever really not be stressful? Does a disarticulated head ever come to seem normal? Apparently. “After a while,” Ali told me during a break from the tutorial, “it’s just a head. You get on with your job.” Michelle told a story from her deployment in Iraq. She was carrying part of a Marine’s leg that had been blown off by an IED. The foot was still in the man’s boot, and presently his buddy went to pull it out. When the boot relinquished its hold, the foot smacked Michelle in the face. She made a face that led me to assume the foot had started to decompose. “It wasn’t decomposed,” she said. “It was a brand-new, blown-off foot.” She leaned closer. “He wasn’t wearing socks.” What repelled Michelle was not blood or gore, not the foot’s detachment from the rest of the body or the awful deadness of it, but the smell and feel of the sweat on her cheek.

  And that will serve as my lurching segue to the miraculous, reviled excretions of the human eccrine gland. In a place like Afghanistan, sweat keeps more people alive than corpsmen do.

  ___________

  * Except when he’s a Godfrey, as he is in many of his 1970s movie credits. Godfrey Daniels produced ten titles in the long-forgotten genre “soft core,” paying loving if needless attention to his plots, one of which could be a chapter in a Mary Roach book: “A research facility uses state-of-the-art equipment to test sex dolls.”

  † And the founder of Missing Something, my second-favorite amputee organization name, after Stumps R Us. I attended a Stumps bowling party in the 1990s, which served as my official introduction to the awesomeness of Hosmer Upper Extremity Prosthetics sporting attachments. In addition to the Bowling Attachment, Hosmer makes a Baseball Glove Attachment, and the pole-gripping Ski Hand/Fishing Hand. The Hosmer-equipped bowlers kicked my ass.

  ‡ But not your iPhone. Smart smartphone thieves use the startle reaction to their advantage. They come up behind unsuspecting texters and whap them on the back of the head. The startled victim’s arms bend, launching the phone, which is effectively tossed to the thief.

  § More formally known as the “optional integrated phallus,” available in Caucasian and African American (different colors, same size).

  ¶ Expendable items like Visceral Linings, Replacement Veins, Foreskins (for the Nasco Circumcision Trainer) and Laerdal’s Concentrated Simulated Vomit are known in the industry as “consumables.” In the case of the Simulated Boluses of chewed food that get stuck in the esophagus of the Laerdal Choking Charlie manikin, the term is doubly apt.

  # I suppose that by “seniors” Cartledge means people older than the boys; however, Spartan senior citizens weren’t the courtly walker-pushers of current stereotype. “Tribal elders” would screen babies for military worth; those deemed unfit were hurled into a chasm called “the deposits.” Nothing in antiquity makes much sense. Who gives cheese to a goddess of vegetation?

  Sweating Bullets

  The war on heat

  FORT BENNING, GEORGIA, HAS three key ingredients for heatstroke: humidity, intense sun, and Army Ranger School. Rangers, like their better-known cousins Navy SEALs, are part of the US Special Operations forces. To borrow the words of their creed, the Ranger is an “elite soldier” expected to “move further, faster and fight harder than any other soldier.” Josh Purvis would seem to be maximally elite in that he was, when I met him, an instructor at Army Ranger School and a contender for the annual Best Ranger Competition. The competition falls into the category of a multisport event, surely the only one to include a Bayonet Assault Course and a litter carry. (They don’t mean trash.) Competitors march and run twenty-plus miles with a sixty-pound pack, and every year, a few will experience a second litter carry, in the horizontal position. In 100-degree heat, “further, faster” can be a lethal undertaking.

  Today Purvis, along with a fellow instructor, will march in a hot spell of mechanical making. As subjects in a heat tolerance study, they will walk fast and uphill for two hours at 104 degrees Fahrenheit on a treadmill inside the “cook box” at CHAMP: the Consortium for Health and Military Performance, part of the Uniformed Services University of the Health Sciences. Some individuals are constitutionally prone to heatstroke and other heat illness, and the Army would like to have a way to know who they are before sending them out into the scorch of a Middle East afternoon with a hundred pounds of gear and other human beings whose lives depend on them.

  Purvis leans against a counter, shirtless, filling out a “mood state” questionnaire. I see him put a check in the “Moderately” column beside the descriptor “full of pep.” Pep isn’t really a word for Josh Purvis. Pep wants some spring to the step, some twinkle, a tendency to whistle. I don’t believe Josh Purvis whistles. His features, while handsome, have a hard set to them, a sort of coiled restiveness.

  The researcher, a fit blonde with a luminous complexion, tells Josh to make a fist. She and her colleagues are looking for biological and genetic markers that might lead to a simple blood test to identify combatants prone to heat illness, so their superiors could keep closer tabs on them. However, her request is unrelated to the drawing blood. “Josh, let us see your muscle.” The researcher is Josh’s mother, Dianna Purvis.

  Josh’s arms remain at his side. “Mom.”

  Purvis the elder holds out an apple from the pre-test meal pack. “Josh, eat your snack before you go in.”

  “Mom, stop.”

  I can’t see which box Josh has checked beside the descriptors Uneasy, Peeved, and On Edge, but I’d mark them “a little bit.” His mother has put this down to “the probe.” He will be having his tolerance tested—heat and otherwise—by way of a rectal probe: a slim, flexible, insertable thermometer. The rectal probe is attached by a six-foot wire to a piece of portable hardware labeled Physitemp Thermes. It is the size of a hardback book, and heavy as a brick. It’s heavy enough that if you set it down on a counter, forget that you are tethered to it, and walk away, you will be very effectively halted before you drag it off the counter.

  The rectal thermometer enables the researchers to monitor their subjects’ core temperature. Like any complex bioelectrochemical system, the human body works best when its vital components are humming along in a set temperature range. For humans, that’s roughly ninety-seven and a half to ninety-nine and a half degrees Fahrenheit. When your core temperature begins to rise, either because it’s hot where you are or you’re toiling hard, or both, the body takes measures to bring it back to the happy range. First and foremost, it sweats.

  Until this trip, I thought of sweat as a sort of self-generated dip in the lake. But sweat isn’t cool. It’s warm as blood. It essentially is blood. Sweat comes from plasma, the watery, colorless portion of blood. (A dip in the lake cools by conduction: contact with something colder. Highly effective but not always practical.) Sweat cools by evaporation: offloading your heat into the air. Like this: When you start to overheat, vessels in your skin dilate, encouraging blood to migrate there. From the capillaries o
f the skin, the hot plasma is offloaded through sweat glands—2.4 million or so—onto the surface of the body to evaporate. Evaporation carries heat away from the body, in the form of water vapor.

  It is an efficient system. A human in extreme heat can sweat as much as two kilograms an hour, over a span of a few hours. “Roughly speaking, 10 kilograms loss of sweat [over the course of a day] is not rare for workers in overheated factories and active soldiers stationed in the tropics,” states the late Yas Kuno, longtime professor of physiology at Nagoya University School of Medicine, in the 1956 edition of Human Perspiration. “One will be struck with wonder . . . when he thinks that such a large amount of sweat is produced from glands which are extremely small in size.” Though humans have, by weight, more than twice as much salivary gland tissue as sweat gland tissue, they are capable of producing six times as much sweat as spit.

  Human Perspiration is itself a prodigious output: 417 pages. There was a lot to report,* in part because Kuno’s sweat studies spanned thirty years, and in part because he had a lot of collaborators: “some 65 in all.” The book includes a collection of black-and-white photographs of Japanese men in thongs, sweating after a session in the Perspiration Chamber. Because the men had been dusted with a special starch that turns black on contact with sweat, their torsos, foreheads, and upper lips are speckled with what appears to be an especially virulent mildew. One set of images highlights the surprising variety of sweat distribution patterns on the human scalp.† Rather than take a razor to their own heads, the researchers recruited “eighteen Buddhist Japanese priests who make it a custom to shave their heads” and, going forward, to ignore all calls from Nagoya University.

  Outside of thermoregulation labs, sweat commands little respect, a fact that needled Kuno. “It is peculiar,” he wrote, “that the value of sweating is appreciated only by patients [who cannot sweat], who suffer greatly from heat, and not by ordinary people, who usually complain about too much sweat.” Jerks. To Kuno’s mind, nothing less than the march of civilization was forged by the indomitable human thermoregulatory system. “The human race inhabits the whole earth, . . . while the living zones for most animals are more or less confined. This privilege of the human race has partly been acquired by their intelligence, but their spreading over the torrid zone has only succeeded through the high development of the sweat glands.” Were it not for human perspiration, there would have been no Vietnam War, no Operation Iraqi Freedom, no Georgia-based Army Ranger School.