Is that so?
I have a Taiwanese dharma teacher (my master's dharma successor)
who had to go through hospital operations. Because of his practise,
no anesthetic could affect him. He got twice the usual dose,
usually one dose is enough to make a person unconscious. However,
he remains fully conscious. He told the doctors and nurses that no
amount of anesthetic could make him unconscious, so go ahead with
the operation. The whole operation went ahead with him fully
conscious, observing everything that happened in the
hospital.
Another similar true story of the 16th Karmapa who died in
1981:
As death approached, he had taken
a half-dozen deadly diseases upon himself. Using his yogic power,
he removed much of their harmfulness, at least for those in his
powerfield. He also allowed the physicians to test their medicines
on him. Some of their findings were amazing: even the highest doses
of sedatives had absolutely no effect on him. He cared for their
well-being and never talked about himself.
On the evening of November 5th, the day of Liberatrice, the doctors
had routinely entered his room. Seeing that his machines had
apparently turned themselves off, all had the same thought, "He's
playing a joke on us." At the very moment, they started up again,
worked for five minutes and then stopped completely. The next
morning, when the staff wanted to remove his body from the bed, the
lineage holders asked if all signs of death were present. They were
not. Karmapa's body was still warm and supple, and especially his
heart center was so hot that one could feel it at a good distance.
This is how he stayed.
http://www.karmapa.org/history/karmapa_16/16ka3_9.htm
Sometimes, persons with high level of cultivation can go beyond
these.
