On the outside, the metal box looks like an oversized bread container. But what’s inside could save an abandoned newborn’s life.

The box is actually a newborn incubator, or baby box, and it could be showing up soon at Indiana hospitals, fire stations, churches and selected nonprofits under legislation that would give mothers in crisis a way to surrender their children safely and anonymously.

Indiana could be the first state to allow use of the baby boxes on a broad scale to prevent dangerous abandonments of infants if the bill, which unanimously passed the house this week, clears the state senate. Republican state representative Casey Cox and child-safety advocates say they’re unaware of any other states that have considered the issue at the level Indiana has.

Cox says his bill is a natural progression of the “safe haven” laws that exist in all 50 states and the District of Columbia. Those give parents a legal way to surrender newborns at hospitals, police stations and other facilities without fear of prosecution so long as the child hasn’t been harmed.

Many children, however, never make it that far. Dawn Geras, president of the Save the Abandoned Babies Foundation in Chicago, said safe haven laws have resulted in more than 2,800 safe surrenders since 1999. But more than 1,400 other children have been found illegally abandoned, nearly two-thirds of whom died.

Cox said his proposal draws on a centuries-old concept to help “those children that are left in the woods, those children that are abandoned in dangerous places.”

Baby boxes, known in some countries as baby hatches or angel cradles, originated in medieval times, when convents were equipped with revolving doors known as “foundling wheels.” Unwanted infants were placed in compartments in the doors, which were then rotated to get the infant inside.

Hundreds of children have been surrendered in modern-day versions in place in Europe and Asia. The devices are even the subject of a new documentary titled The Drop Box, which chronicles the efforts of a pastor in Seoul, South Korea, to address child abandonment.

Supporters contend the boxes can save lives by offering women who can’t face relinquishing a child in person a safe and anonymous alternative to abandonment or infanticide.

But critics say the boxes make it easier to abandon a child without exploring other options and contend they do nothing to address poverty and other societal issues that contribute to unwanted babies. Some baby hatches in China have been so overwhelmed by abandonments in recent years that local officials have restricted their use or closed them.

The United Nations Committee on the Rights of the Child has called for a ban on the boxes in Europe and has urged countries to provide family planning and other support to address the root causes of abandonments, according to spokeswoman Elizabeth Throssell.

Whether the US is ready for the boxes is a matter of debate. Geras said many parents who surrender their children at safe haven sites need medical care that they won’t get if they leave the baby in a box. Handing the child to a trained professional also provides an opportunity to determine whether the mother simply needs financial support or other help to develop a parenting plan.

“If you use a baby box, you have stripped away that option,” Geras said. “There’s a lot of things that need to be done to improve safe haven laws throughout the country, but that’s not one of them.”

A better approach, she said, is for states to spend more money to promote their existing laws.

Monica Kelsey, a Woodburn, Indiana, firefighter and medic who is president of Safe Haven Baby Boxes Inc, said the boxes aren’t meant to circumvent the laws that already exist. Instead, they’re part of a broader approach that includes increasing awareness about the laws and other options available to new mothers in crisis.

“If these boxes are the answer, great,” she said. “We’re trying to come at it from all angles.”

Kelsey, who was abandoned in a hospital shortly after her birth because her mother’s pregnancy was the result of rape, suggested the boxes to Cox and has formed a nonprofit that is working with a Fort Wayne, Indiana, company to develop a prototype. It would be about two feet long and be equipped with heating or cooling pads and sensors that would set off alarms when the box is opened and again when a weight is detected inside.

The boxes also would include a silent alarm that mothers could activate themselves by pushing a button.

“We’re giving her the power to do what’s right,” Kelsey said. “We’re hoping that these girls know that once they push that button, their baby will be saved.”

She stressed that the boxes should be viewed as a “last resort” and would include a toll-free number staffed 24 hours a day by a counselor who would first ask the caller to surrender the baby to a person.

The state health department would regulate the boxes. Cox’s bill, which covers children up to 31 days old, also would create a public registry listing box locations.

Kelsey said the bill expands safe haven locations to include churches and established nonprofits that deal with child-welfare issues to ensure that everyone has access.

“We want these locations to be able to accept a child if somebody ... thinks this is the only thing they can do,” she said.