How do certain individuals, like Quang Duc, develop the ability to remain calm when enduring significant nociceptive pain? A famous picture depicts Quang Duc self-immolating himself in protest of the Vietnam War. David Halberstram: "As he burned he never moved a muscle, never uttered a sound [...]. His face  seemed to remain fairly calm until it was so blackened by the flames  that you couldn’t make it out anymore." I'm ignoring shock and hormonal responses in this question, as he remained calm during the initial stage of the burning (where these effects are unlikely to have been live). I'm also (perhaps wrongly) assuming that he wasn't under the influence of drugs and didn't have a cognitive impairment that made him unable to feel the pain. 

A question like this has been asked before on Quora, but I'm not satisfied by any of the given answers. Specifically:


Based on personal/anecdotal experiences, I'm not convinced that confidence/motivation/conviction or any rationalization is able to trigger this ability.
I also don't see how one can use deliberate practice in this task (i.e., build up tolerance with systematic desensitization or connecting the pain signal with positive thoughts/experiences) without seriously damaging the body.
I'm also not convinced that traditional/standard mindfulness meditation has this kind of efficacy. I remember seeing various efficacy quantities of mindfulness meditation (and therapy) in a meta study and none of them seemed to be at the quantity required to remain calm in response to this extreme stimulus.
I'm also skeptical that detachment is viable in this scenario, given the sheer magnitude of the nociceptive stimulus (also, I was under the impression that Buddhist meditation advises the practitioner to be aware to the pain, not detach from it).
If the explanation is elevated gamma-wave activity, how does one reliably reach this state "on-demand" and how does one maintain it during the endurance of significant nociceptive pain?


I should note that I'm not sure how different the mindfulness-based techniques of today are from the Buddhist meditation practiced by Quang Duc.

Perhaps the research shows that one of the points I'm skeptical about is actually effective in remaining calm in the face of extreme pain. If so, I'd love to hear about it.
As mentioned in Can calmness happen during the fight-flight response?, with looking at the possibility of calmness during stress and trauma, you only have to look at the situation with rape victims and soldiers witnessing severe traumatic events who dissociate (Ellert, et al. 2011)(Waller, et al. 2001) during the event.

Dissociation is a psychological defence mechanism (Cardeña, 1994) which helps the person to get through the situation with as little harm as possible.  Think about it like throwing a switch on conscious awareness.

Whilst some define dissociation as a combination of 2 distinct psychological mechanisms (Brown, 2006), the psychobiological mechanism of dissociation is little understood; but, when someone is dissociated from the event, the detachment of conscious awareness from the event can make the person appear very calm.

With Thích Quảng Đức, I would hypothesise that he somehow managed to "mentally switch off from the event" by dissociating through detachment.  Quảng Đức set light to himself as a protest because he felt there was no other way to convey such a strong message. As far as he believed, he had no choice, just like rape victims and soldiers can have no choice.

The thing with the football fan at the Bradford Fire @Robin mentioned, was that he was inevitably pumped full of adrenaline from his adrenal glands to assist in the Flight/Fright response. Cortisol is also released at the same time and Cortisol is good for numbing any present pain in order for you to flee.

Fear of impending pain could activate the flight/fight response releasing the Adrenaline and Cortisol which could be what was happening in the scenario mentioned in the question.

Needless to say that once the Cortisol has lowered he will feel the pain caused.

References

Brown, R. J. (2006). Different types of “dissociation” have different psychological mechanisms. Journal of Trauma &amp; Dissociation, 7(4), 7-28.DOI: 10.1300/J229v07n04_02

Cardeña, E. (1994) The domain of dissociation. In: Dissociation: Clinical and theoretical aspects, Edited by: Lynn, S. J. and Rhue, J. W. 5–31. New York, NY: Guilford Press.

Ellert R. S. Nijenhuis PhD &amp; Onno van der Hart PhD (2011) Dissociation in Trauma: A New Definition and Comparison with Previous Formulations, Journal of Trauma &amp; Dissociation, 12(4), 416-445.DOI: 10.1080/15299732.2011.570592

Waller, G., Hamilton, K., Elliott, P., Lewendon, J., Stopa, L., Waters, A., ... &amp; Hargreaves, I. (2001). Somatoform dissociation, psychological dissociation, and specific forms of trauma. Journal of Trauma &amp; Dissociation, 1(4), 81-98.DOI: 10.1300/J229v01n04_05