A team of researchers put forward a theory of "sudden body fluid vaporization" for the victims' cause of death, and it is just as horrific as it sounds.

It’s hard to imagine a more horrendous way to go than death by volcano, but a new study might have done just that.

A group of researchers from the Frederico II University Hospital in Naples published in PLOS One last month the theory that some victims of the Mount Vesuvius eruption died after the extreme heat of the explosion caused their blood to boil and their skulls to consequently explode.

In 79 AD when Mount Vesuvius erupted, it launched volcanic ash, gas, and rocks for almost 21 miles, and for two days molten lava poured out. Those who lived in surrounding cities like Oplontis, Pompeii, and Herculaneum and did not evacuate in time, all met gruesome ends. And the new research suggests that some might have had more grisly deaths than others.

In the city of Herculaneum, located only four miles from the volcano’s mouth, 300 people took shelter in 12 waterfront chambers along the city’s beach. They all perished once the volcano erupted and they were trapped inside for thousands of years before a team of excavators discovered them underneath several feet of ash in the 1980s.

For the new report, the team studied the skeletal remains of some of the victims inside these chambers. When they first began to analyze the remains, they discovered a mysterious red and black residue covering the bones, inside the skull, and in the surrounding ash-bed where the victims were found.

Several tests were run on the residue and it was discovered that it contained traces of iron and iron oxides, which are created when blood vaporizes.

“The detection of such iron-containing compounds from the skull and the ash filling the endocranial cavity…strongly suggests a widespread pattern of heat-induced hemorrhage, intracranial pressure increase and bursting, most likely to be the cause of instant death of the inhabitants in Herculaneum,” the study said.

The waterfront chambers would have basically turned into ovens when the volcano’s ash and heat rained down. The researchers estimated that the temperature inside the chambers must have reached around 500 degrees Celcius (or 932 degrees Fahrenheit), which would cause the blood of anyone inside to boil and their skull to explode.

Several of the skeletons the team examined had skulls with gaping holes and stains that are consistent with “recurrent skull explosive fracture.”

Those who died in Pompeii, which was located a couple miles further from the volcano than Herculaneum also died instantly but didn’t go quite as horrendously.

“In Pompeii, placed about six miles from the vent, the lower temperature of about 250 – 300 degrees Celcius was sufficient to kill people instantly, but not hot enough to vaporize the flesh of their bodies,” Pierpaolo Petrone, lead scientist of the study, told Newsweek.

While the scientists’ hypothesis is certainly gruesome, it is also very important for the future study of the still-active volcano.

According to the study, archaeological and volcanological site evidence shows that Mount Vesuvius has a major eruption every 2,000 years. The last major eruption was nearly 2,000 years ago and so research points to another catastrophic event sooner rather than later.

This could mean big trouble for the three million people who currently live near the volcano.

Next, check out Mount Nyiragongo and its bubbling hot lava lake. Then take a look at the devastation of Mount Pelee, the worst volcanic disaster of the 20th century.