Researchers with the Miami Project to Cure Paralysis are performing much of the current research into the potential treatment. Dalton Dietrich, professor of neurological surgery at the Miami Miller School of Medicine and scientific director of the Miami Project, said the use of hypothermia goes back as early as the 1960s for cardiac procedures -- though the side effects associated with drastically cooling people down were considerable.
Now, Dietrich said, researchers are looking toward a more modest cooling effect to prevent further nerve damage after a spinal cord injury.
"Over the last 15 to 20 years, in experimental models of brain and spinal cord injury, we have shown that modest cooling -- 2 to 3 degrees centigrade -- is protective and improves outcome," he said.
The fact that treatment began so soon after the injury may have made a big difference.
"The window of opportunity to introduce hypothermia may be relatively short," Dietrich said. "Hypothermia and other treatments have to be initiated early after injury. Thus, unless patients get to the hospital within two to three hours, many therapies are no longer potent in terms of targeting the injury mechanisms that they are directed toward."
Other doctors, however, cautioned that it is too early to say exactly how much the treatment helped.
Some say other factors may have also played a role in his improved prognosis. Injection of the steroid methylprednisolone, which Everett is also believed to have received, could have limited the swelling that follows spinal injury. And Everett's spine was repositioned quickly following the incident -- another crucial step.
"That may be what helped the most," said Dr. Thomas Balazy, a spinal cord injury team supervisor at Craig Hospital in Colorado. "They got him to the acute care hospital, and then aligned his neck, decompressed the cord and took the pressure off it, and stabilized his neck."
Most of the controlled experiments to determine the effectiveness of hypothermia as part of medical treatment have so far been done only on animals, though a handful of human case reports exist.
"Hypothermia is often listed as a promising neuroprotective therapy but one that needs further clinical testing before it should be used as a standard of care in treatment of spinal cord injuries," said Naomi Kleitman, director of the Repair and Plasticity Program at the National Institute of Neurological Disorders and Stroke.
And hypothermia isn't without its dangers. Even modest cooling of the body can have significant health effects.
"Overcooling or prolonged hypothermia can have some detrimental effects on organs that require higher blood flow to respond to the stress of the neurological injury," said Dr. Michael Haak, assistant professor of orthopedic surgery at the Feinberg School of Medicine of Northwestern University.
"Sometimes you get into problems such as blood clotting and other side effects related to blood disorders," Hall added.
For now, Everett remains in intensive care, though he is awake and communicating with his family. Though doctors remain hopeful, only time will tell whether he will recover fully.
"These cases are extremely complicated, and it will take several weeks to determine the extent of Mr. Everett's conditions and potential for recovery of function," Dietrich said.