Sgt. Kim Eimers understands now why her father never talked about his time as a soldier in Vietnam. When she gets back from Iraq, where she's stationed with the Fourth Infantry Division in Baqubah, she doesn't think she'll talk about her wartime experience much, either. Her own worst moment came when a mortar round hit her mess hall at the Third Brigade's base, during dinnertime. "I just lost it," she says. But so far her family still hasn't heard about the incident.

Capt. Glenn Palmer's worst moment came when he was giving mouth-to-mouth resuscitation to a wounded officer who had been shot by a sniper while riding in the back seat of a Humvee. Palmer, who had been driving the vehicle, kept trying to blow, even after he felt his own breath whistling out of a hole in the victim's head. "I still can't get the taste out of my mouth," says Palmer, an Army chaplain.

Like soldiers in every war, American men and women in Iraq have seen things they'll never be able to discuss easily. Some feel damaged in a way that can't be repaired; some will find that nightmares begin only many years later. In World War I, the condition was called shell shock, and doctors treated it in psychiatric hospitals. World War II's psychologists termed it battle fatigue, and Vietnam's shrinks coined the terms traumatic stress and posttraumatic stress disorder (PTSD). Today, the preferred term is combat stress, and the military has an official policy for dealing with it--in the field, as close as possible to the fighting.

Combat-stress units are deployed throughout Iraq, staffed by professionals who give soldiers counseling and advice. The military hopes that by easing soldiers' troubles in real time, and teaching them how to deal with the horrors of the job, it will reduce the wave of psychological fallout that always follows a war. Yet combat-stress teams are controversial. Some soldiers feel stigmatized when offered treatment in the field, and some officers believe it gives soldiers a psychobabble excuse for malingering. The Marine Corps will field its first permanent combat-stress units in the coming months.

War-related stress has many symptoms: irritability, frequent urination, diarrhea, tingling in extremities, sudden reaction to loud noises, insomnia, weight loss, even balding. And the basic treatment in the field is simple, best expressed as "three hots and a cot." Counselors recommend that stressed soldiers check into special "fitness centers" with real beds, hot food and 24-hour counseling--where they are encouraged to sleep and relax as much as they want for three days. After that, most soldiers are ready to go back to work.

It certainly helped in Sergeant Eimers's case. "Before it was the stress of the heat, and then it was the stress of the mortars--we've had 90 since October," she says. The one that hit near her mess hall, a structure with a fabric roof, sparked a panic as soldiers jammed into one another trying to get out the doors. She wasn't sure she could go on soldiering after that. During counseling, Eimers was relieved simply to know that she wasn't alone in feeling anxious.

Sometimes, stressed GIs get more than just therapy and advice. Capt. Robert Ruxin, a stress-team psychiatrist, says in about a quarter of cases antidepressants are prescribed. The drugs of choice in Iraq are Celexa and Trazodone. Army Sgt. Janice Smith, who is stationed in one of the hottest areas of the Sunni Triangle, says she takes anti-anxiety pills to help her cope. "I don't know if I will ever be able to live a normal life again," she says. "It's very hard for us not to be stressed out when soldiers are dying every day around you."

Some cases cannot be treated in the field. In all, a total of 538 soldiers in Iraq have been "sectioned out," or sent home for treatment of psychological problems. (The military says many of them had pre-existing mental disorders.) Still, although the Army will not divulge the overall number of GIs who have received counseling in Iraq, combat-stress treatment does seem to help keep soldiers on duty. At the 528th Combat Stress Detachment, counselors see from two to 20 people a day. In Balad, the 113th Medical Company's fitness center typically has a caseload of four soldiers in the three-hots-and-a-cot program, plus a couple of dozen soldiers who get walk-in treatment every day. Half a dozen other combat-stress teams are deployed around Iraq.

Some stress-reduction doctrine does have a touchy-feely aspect--talk of "identifying stressors," and therapy that includes breathing and relaxation exercises--that seems to clash with the standard military ethos. Capt. Robert DeCarlo, a counselor in Baqubah, says his advice to soldiers is often as simple as doing something familiar. "I like to bake a cake... getting a homemade cake really makes people happy." So his C-Hut looks like a Betty Crocker ad, stacked with cake mixes sent by friends and family through the military postal service. He shares his creations with his clients. The combat-stress team at Camp Warhorse actively promoted Christmas decorations as a morale booster, with a DVD player as a prize for the best-decorated hooch.

In a "normal" war, only 10 percent of the Army's forces would be in frontline combat roles--the others would have support duties and be far from harm's way. Yet in Iraq, all U.S. forces are effectively in combat roles. Typically, 25 percent of frontline soldiers will suffer from combat stress, experts say. Not all of those will go on to get full-blown posttraumatic stress disorder. But even in Gulf War I, studies put the number of PTSD victims at 5 percent to 10 percent. In Iraq, with a much longer engagement and nearly all troops potentially in harm's way, the rate could be much higher.

Lt. Col. Daniel Lonnquist, an Army Reserve psychiatrist who works with the stress teams in Baqubah, says he feels a strong sense of deja vu there. In his civilian practice, he works for the Veterans Administration, counseling Vietnam vets. At 58, he's also a Vietnam veteran himself, a rarity among troops in Iraq. "There's a lot of macho attitude here," he says. Among the Vietnam vets he sees back home, some "took 15 years to deal with their feelings about killing somebody," he says. "We have vets who for years said 'counseling is not for me' and then had to eat humble pie." In some respects, he thinks this war will be worse; a greater proportion of the soldiers are exposed to risk, many more are reservists and, unlike Vietnam, there's been a great deal of uncertainty about how long their tours will last. "I tell these guys, 'Talk about it with your buddies here because they'll understand... no one else will'."

Captain Palmer has memories he'll never be able to purge. "I have buried babies caught in the cross-fire and held the hand of wounded soldiers while the doctor tries to save their eyes and legs," he says. But the hardest was trying to resuscitate that fellow officer, who died in the field. Palmer called on the combat-stress team for counseling, both for himself and for other soldiers involved. The initial interview is called a critical-event debrief, or CED; the idea is to get soldiers talking about what they experienced, and to leave a door open for future counseling. Within a day Captain Palmer was back in the field himself--doing CEDs for other anxious soldiers.

Within the military, a big selling point for the combat-stress teams is that they keep soldiers fighting; in military parlance, frontline psychologists are a "force multiplier." The soldiers themselves sense a Catch-22 in that: getting stress relief so you can experience more stress. Lt. Marivic Fields was giving a combat-stress-prevention class for the 51st Transportation Company at Camp Anaconda recently, in a tent darkened to prevent targeting by enemy mortars. The assembled soldiers were convoy truckers; their jobs are among the most dangerous in Iraq now. "This deployment too shall pass," Fields told the group. "Like a kidney stone, it'll hurt, but it'll pass."

"Hey, lieutenant," called one of the soldiers in the back. "You want to get rid of our stress, send us home!"

"Hooah!" they all yelled.