Here’s something that will keep you up at night.

A TikToker has revealed hidden dangers that could be lurking in plain sight in your bedroom.

“There have been so many lawsuits about this. It’s kind of insane that this is a thing,” explained a woman who goes by Kezi, who was covered in head-to-toe personal protective equipment (PPE).

The reason for the heavy-duty hazmat fit? Fiberglass from her mattress.

Fiberglass, made of glass fibers that are formed by forcing molten glass through tiny holes, is used in mattresses as a flame retardant. If there’s a fire, the slow melting of the glass fragments creates a barrier between flames and more combustible materials.

Fiberglass is typically woven into mattress material directly beneath the inner mattress cover. According to the Sleep Foundation, memory foam mattresses are more likely to contain fiberglass.

Mattress manufacturers opt for fiberglass as a flame retardant in their products as the material is lightweight, affordable and chemical-free … so long as it doesn’t leak out of the mattress, which is precisely what happened to Kezi, who inadvertently released unholy fiberglass hell on herself when she unzipped her memory foam mattress in an attempt to spot clean it.

“I saw these particles in the air and went, oh s–t, that’s fiberglass.”

She had to cull her bedroom as a result of the accidental unleashing.

“I have had to toss out my entire mattress, all of my pillows, anything that had insulation in it, my duvet, all of that, and now I’m having to spend my entire week like this because I unzipped it,” she said.

In one of her videos, Kezi implored others to be cautious when choosing or caring for a mattress.

“Memory foam mattresses should not have fiberglass in them,” she said. “If you have a memory foam mattress, do not try to unzip it, spot clean it or throw the thing in the washing machine. Throw the s–t away, to be completely honest.”

If inhaled or ingested, fiberglass can perforate the tissues of the body.

Immediate risks from fiberglass exposure include skin rash, eye irritation and scarring, stomach issues and breathing problems.

Long-term effects of fiberglass exposure can include hormonal disruptions, lung disease, pulmonary fibrosis and lung cancer.

What makes airborne fiberglass particularly dangerous is its microscopic size, which allows it to travel to every part of the home, including air ducts, air conditioners, furniture, carpets and clothing.

Even more disconcerting is that many people do not realize they’ve been exposed to fiberglass until symptoms develop.

Experts say that as long as fiberglass is contained, humans are relatively safe from adverse health effects. For extra protection, they recommend a mattress protector.

Commenters were quick to call out the “nightmare” situation and the “toxic” substance.

In her original video, Kezi solicited help for treating her clothing in the fiberglass fallout. In a follow-up video, she upgraded her face covering to a respiratory mask and posted a status update.

“As far as the clothes, a lot of stuff had to be tossed out, and it’s very disheartening,” she said. “However, there are a lot of clothes that only had fragments on them.”

She added: “So I did what you guys said. I got a pet lint roller, and I lint-rolled all of them using my phone flashlight to kind of see where the shards are.”

She laundered her clothing carefully, adding vinegar to the washing machine, using the cold water setting and drying the clothes.

If more shards were visible, she repeated the process.

To protect the rest of her home, Kezi blocked off the unaffected areas.

“Luckily, it’s a hallway that the room is in, so I tarped off the rest of the house,” she explained.

“Got a HEPA vacuum and then Swiffer with vinegar, a ton of vinegar and water, Swiffer down the walls.”

She vacuumed “incessantly” and cleaned all of the floors and walls repeatedly.

She admitted that the process was “extremely tedious and very exhausting,” recommending folks check manufacturing labels on their mattresses.

“Check your mattresses, check to see if they are fiberglass-free.”

However, not all mattress labels explicitly list fiberglass among their materials.

Manufacturers may use alternative terms such as “glass wool” or “glass fibers.”

While some mattresses are certified as being free of heavy metals and hazardous flame-retardant chemicals, these guarantees are only applicable to the mattress foam, meaning chemicals may still be present in mattress covers, and people can be unwittingly exposed to fiberglass in their “chemical-free” mattresses.

In 2023, California enacted legislation that makes it illegal to use fiberglass in mattresses, mattress covers or other upholstered furniture.

In general, latex and organic mattresses are not made with fiberglass. Daniel Gartenberg, CEO of SleepSpace and chief sleep scientist at CPAP.com and MDbiowellness, previously told The Post that an organic mattress is well worth the higher price tag.

“Organic mattresses reduce your exposure to potentially toxic flame retardants, VOCs (volatile organic compounds) and synthetic materials that can off-gas while you sleep,” he said. “It’s an investment not just in sleep, but in long-term health.”