A brightly colored squishy cube sits harmlessly in a child’s hand — soft, stretchy and designed for one simple purpose: to be squeezed.

But doctors are now warning that one of the world’s most popular sensory toys can become dangerously hot, burst without warning and leave children with severe burns when exposed to heat, freezing conditions or a microwave.

The growing alarm centers on NeeDoh toys, the wildly popular stress-relief gadgets marketed to children as fun, tactile “fidget” toys. Across social media, videos have encouraged users to heat, freeze or microwave the toys to see how they change.

Doctors say the results can be devastating.

Children have reportedly been rushed to hospitals with burns to their faces, hands, arms and bodies after the toys burst and sprayed sticky, heated material onto their skin. In some cases, the injuries have been so severe that children needed skin grafts, specialized burn treatment and lengthy recovery.

In one case, a 7-year-old Missouri girl, Scarlett Selby, was placed in a medically induced coma after a NeeDoh toy exploded after being heated in a microwave.

Her father described hearing a scream that instantly told him something was terribly wrong.

“It all happened so quickly,” he said. “I heard her scream, and it was like a blood-curdling scream.”

The toy’s heated contents reportedly coated the child in a thick, molten substance that clung to both her skin and clothing. Her father struggled to remove it without causing further damage.

That is what makes these injuries especially frightening, doctors say.

NeeDoh toys are typically filled with a gooey material that can transform under extreme temperatures. One popular version, the Nice Cube, contains a natural sugar-based filling that can expand rapidly when heated. Pressure builds inside the toy — and when it bursts, the substance can splatter across a child’s face or body.

The manufacturer’s warning is clear: Do not heat, freeze or microwave the toy.

But online videos and schoolyard curiosity can overpower a warning label in seconds.

Dr. Alicia Webb, a pediatric emergency medicine physician at Children’s of Alabama, said the danger is not limited to one isolated accident.

“I personally have taken care of several children and teenagers who have been burned while participating in the current NeeDoh microwave trend,” Webb said.

She warned that the toys can explode when heated, causing burns to the face, eyes, mouth and body. There is also concern about internal injury if the hot material is swallowed.

For children, even a brief exposure can cause serious damage.

Dr. Michael Cooper, director of Burn at Northwell’s Staten Island University Hospital, explained that children’s skin is thinner and more delicate than adults’ skin, allowing heat to penetrate more quickly and deeply.

“Even a brief contact with a hot substance can cause significant tissue damage,” Cooper said.

The cases emerging from around the world are difficult to ignore.

In the United Kingdom, a 10-year-old girl named Bella reportedly suffered serious facial burns after a TikTok-inspired challenge involving a NeeDoh-style toy. Her mother said she was referred to a burns unit and warned to avoid sun exposure for at least two summers because doctors were unsure whether the injuries would scar.

In Chicago, a 9-year-old boy, Caleb Chabolla, reportedly suffered second-degree burns after a microwaved toy burst across his face. Doctors had to remove damaged tissue caused by the hot, sticky substance.

And in New Mexico, a 13-year-old girl reportedly suffered third-degree burns after a toy left inside a hot car exploded when she squeezed it.

Her mother recalled the terrifying moment her daughter ran from the vehicle in agony.

“She jumps out of the car and she’s like screaming at the top of her lungs like, ‘Please momma, get it off,’” she said.

The concern is not simply that children are copying viral videos. Doctors say these trends can travel quickly through friends, classrooms and word of mouth — even among children who do not regularly use social media.

“Parents need to be aware of this trend and all dangerous social media challenges because they can pose a serious risk to children,” Webb said.

She urged parents to talk openly with children about the videos they watch and to remind them that viral clips often do not show the painful consequences that can follow.

The message from doctors is simple: these toys should only be used as intended.

Parents are being urged to keep NeeDoh toys and similar sensory products away from microwaves, ovens, hot cars and extreme temperatures. Toys that are cracked, leaking or damaged should also be removed from use.

And when a burn happens, experts say immediate action matters. Cool running water should be used on the affected area, while serious burns — particularly those involving blistering or the face, hands, feet or large areas of the body — require urgent medical attention.

“A moment of curiosity or experimentation can lead to injuries that require months of treatment and recovery,” Cooper warned.

For families, the lesson is sobering.

What looks like a harmless toy on a bedroom floor may become something far more dangerous when mixed with heat, pressure and one viral challenge.