Border detention facilities like those where 8-year-old Guatemalan migrant Felipe Alonzo-Gomez fell fatally ill while detained by Border Patrol are no place for children—healthy or otherwise—top medical experts told The Daily Beast.

The boy’s death, the second of a detained migrant child in just over two weeks, spurred promises by Homeland Security Secretary Kirstjen Nielsen to inspect borderland stations and to order “more thorough hands-on” medical screenings of the 1,400 to 1,500 minors held at the U.S. border on any given day.

But medical professionals and human rights advocates said that short of completely ending the policy of holding children in such centers—called hieleras, Spanish for “iceboxes,” because of their frigid temperatures—there is little that can prevent more kids from getting dangerously sick.

“There’s no amount of detention that has been found to be good for children,” said Dr. Alan Shapiro, a pediatrician and co-founder of Terra Firma, an organization that provides medical care to undocumented immigrant children. “Children should never be placed in these detention centers... Being in these large facilities where there’s not proper monitoring, it’s very easy for things to go wrong very quickly.”

“This father, if he and his son had been in the community, might have been able to access medical services in a more timely fashion,” Shapiro added. “Being detained, they didn’t have that option.”

The notion that minor immigrant children can be indefinitely and humanely detained is a contradiction in terms, experts said.

“They have very cursory medical attention,” Shapiro said, adding that many of the examinations are conducted by law enforcement officers, rather than medical doctors, and are frequently limited to checking for lice, scabies, or chickenpox.

The lack of medical professionals is particularly perilous for children, whose care presents unique challenges.

“Children are not little adults—they don’t present like little adults,” said Dr. Julie Linton, co-chair of the American Academy of Pediatrics Immigrant Health Special Interest Group and a practicing pediatrician. “They may have subtle changes like a fast heart rate or fast breathing, they may not be able to report their symptoms, they may stop talking due to stress, they may be throwing a tantrum due to stress.”

“That’s why it’s so critical to have access to pediatric medical experience, somebody who can pick up subtle changes and deterioration” before the child’s condition declines too rapidly to treat—as it did with Felipe and with 7-year-old Jakelin Caal Maquin, who died after being detained two weeks earlier.

After being apprehended by Border Patrol east of El Paso, Texas, Felipe and his father were shuffled to three different detention facilities over the course of six days, according to a Homeland Security timeline. The Department of Homeland Security is normally barred by court order from holding minors in such facilities for longer than 72 hours, but has defended holding Felipe for nearly twice as long by noting that the agreement only covers unaccompanied minors.

After six days, border agents noticed that the child had a cough and “glossy eyes,” and transported him to Gerald Champion Regional Medical Center in Alamogordo, New Mexico. Despite a 103-degree fever, Felipe was diagnosed with the common cold, prescribed an antibiotic and discharged to a cell within a Border Patrol highway checkpoint on the outskirts of town.

With no medical staff on duty at the checkpoint, Felipe’s condition worsened—according to his stepsister, he began vomiting blood. The boy died on Christmas Eve, less than an hour after losing consciousness on the way back to the hospital.

The investigation into Felipe’s death remains ongoing, although the New Mexico Office of the Medical Investigator released a statement on Thursday revealing that nasal and lung swabs conducted during his autopsy tested positive for influenza. The virus, according to the Centers for Disease Control, generally has an incubation period of one to four days, meaning that Felipe was likely infected while in detention.

Hospital officials, citing medical privacy laws, declined to say whether they had tested Felipe for the flu while he was in their care.

Pediatricians told The Daily Beast that the conditions inside Border Patrol’s hieleras would exacerbate almost any medical problem—particularly an infectious disease in a school-age child. Those stressful conditions, coupled with a demonstrated lack of access to proper medical care, could easily have contributed to Alonzo-Gomez’s declining health.

“The conditions to which he was subject are not supportive of recovery, and also, because of the stress of the experience, place children at very high risk for infectious diseases,” Linton said. “When children are sick, exposure to stress hormones makes it much more difficult to recover from illness.”

After making the journey to the U.S.-Mexico border from the so-called “Northern Triangle” countries of El Salvador, Guatemala and Honduras, which can take weeks or even months, Shapiro said, many are already in precarious medical states before even entering U.S. immigrant detention.

“Children are exposed to the elements, they suffer from hunger, some of them are injured or have become sick along the way, and also the forms of transportation can be quite dangerous,” Shapiro said. “All of these things put children at risk for a weakened physical state.”

The stress of the journey is compounded by the conditions inside immense, “warehouse-like” immigrant processing facilities, said Linton, noting that many children are forced to sleep under 24-hour artificial lights, with open toilets, no showers or sinks for brushing teeth, and only thin Styrofoam mats between their bodies and freezing concrete floors.

“Imagine coming from a very harrowing journey, and being subject to having the lights on 24/7,” Linton told The Daily Beast. “The effect that stress has on your body is tremendous, particularly while you are recovering, in the cases of these two children, from very serious illness.”

Combine weakness from the journey, little sleep, unpalatable food—“almost everywhere I hear children are given warmed-up frozen burritos,” Shapiro said—and close physical proximity to scores of other migrants, and the facilities become a virtual breeding ground for communicable diseases.

“It’s like daycare—children are going to be more exposed to contagious infectious diseases,” Shapiro said. “It is really concerning that this child, who had the flu, was moved to various places, and it makes me wonder how many other people, even the workers, were exposed to him.”

Even members of the Homeland Security Advisory Council, which advises the Department of Homeland Security and the White House, say that the conditions in the detention facilities are crowded and unsanitary.

One individual from the council told The Daily Beast that he traveled with several members to the border in California and Arizona to visit six different sites, with a focus on studying conditions for women and children. The most alarming part of the trip, the source said, was the sheer number of people living in holding centers—the facilities that serve as the first stopping point for those who enter the U.S. from the southern border.

Border patrol agents are supposed to transfer individuals from those stations to official detention centers within 24 hours, the source said, but are holding them for “far longer.”

“There are bottlenecks along the way, too,” the advisory council member said. “The way the laws and regulations are set up, one part of Border Patrol can’t turn people over to ICE who can’t turn it over to the next team of people. They just don’t have the resources.”

The source said he spoke with people who crossed the border, including women and children, who had broken bones and wounds.

“Some of them I think had tried to scale the wall and jumped to the ground,” the source said, adding that the detention centers were overcrowded and did not offer a separate space for those suffering from various illnesses.

On the first day of a two-day swing through Texas and New Mexico border country following mounting public outrage over the children’s death, Nielsen toured multiple U.S. Customs and Border Protection stations and substations in West Texas “to see first-hand the medical screenings and conditions” at the facilities.

Days earlier, Nielsen blamed the deaths, as well as the larger ongoing crisis at the border, on “smugglers, traffickers, and their own parents,” adding that “bad judicial rulings from activist judges and inaction by Congress” had pushed Homeland Security to its breaking point.

Nielsen announced that she asked the Department of Defense to provide additional medical professionals at the border and increased medical examinations of minors apprehended at the border. “Moving forward, all children will receive a more thorough hands-on assessment at the earliest possible time post-apprehension,” Nielsen said.

But the lack of specificity in the proposed policy changes left health experts concerned that Nielsen does not understand the scope of the problem.

The secretary’s statement, Shapiro said, “doesn’t call specifically for pediatric specialists. Without having medical personnel that are trained and specialize in pediatric care, we are concerned that problems will continue to be missed.”

“I don’t believe that what she’s asking for is enough, and specific enough,” Shapiro added.

The Department of Homeland Security’s use of a vague term like “medically trained agents and officers”—a department official declined to specify who was included in that group—makes it “very difficult to interpret what that announcement means in actual policy,” said Linton.

But the doctors also said that no policy changes can mitigate the negative effect that detention has on children’s health.

“Anything short of not having children be processed in processing centers falls short of the standard of care for children,” Linton said. “We’re not going to be able to prevent every death of every child... We’re saying that children do, however, deserve access to pediatric care, to conditions that are supportive of their health and well-being.”

Rep. Steny Hoyer, a Maryland Democrat who is expected to serve as House Majority Leader in the next Congress, announced this week that the House will hold hearings “to ask serious questions about what happened and who bears responsibility” for Felipe’s and Jakelin’s deaths.

That call was echoed on Friday by Sen. Dianne Feinstein, who will serve as ranking member on the Senate Judiciary Committee.

“These heartbreaking incidents are sadly consistent with previous reports of widespread abuse of children in immigration custody and the judgement of medical and mental health organizations that Border Patrol facilities are not adequately staffed or equipped to properly care for children,” Feinstein said in a statement. “Our committee is uniquely situated to examine these issues and I hope we can schedule a hearing immediately in the new year.”

A spokesperson for Sen. Lindsey Graham (R-S.C.), who is widely expected to serve as the committee’s chair, declined to say whether he would permit such a hearing.

— Erin Banco contributed to this story.