"In meditative states, the monks had remarkable control over their body temperature and oxygen intake. They could use their body heat to dry wet towels placed around them, where most people would shiver uncontrollably. They could raise the temperature of their fingers and toes by as much as 17 degrees. Some could even spend a night on a rocky ledge at an elevation of 15,000 feet in the Himalayas, where temperatures fell to zero degrees Fahrenheit, while they wore only woolen or cotton shawls. "

How well has this been replicated? Has a non-buddhist person ever been able to demonstrate similar feats?

It's such an astounding claim. I want to believe, but am still skeptical because it just so astounding.