The Neurological Side of Firewalking

“There’s no logical explanation.”
    -Ron Sato, MD
    Stanford Medical School, Burns & Plastic Surgery


    Firewalking, or coalwalking as it is also known, is the practice of walking a short distance on a bed of hot ambers. This ceremonial tradition, which has recently spurred widespread interest in the mind-body connection, induces a sense of euphoric achievement. Firewalking has served as a cultural ritual, and for many societies throughout history has acted as a rite of passage indicative of great personal and spiritual maturity (6). In its newer commercialized state, firewalking is practiced as a form of corporate team-building wherein co-workers bond over each other’s success. While skeptics are quick to point out the possible thermodynamic explanation of firewalking (the “conduction hypothesis”), the exact neurological and mental aspects are less well known. On first glance, it seems ridiculous that someone could walk on hot coals without charring their flesh or experiencing great pain. By taking a closer look at the neurobiological element of the firewalk, we may be able to more fully understand this bizarre phenomenon.

    A firewalk involves extensive preparation, wherein wood is burned to a charred ashen state and the coal bed is churned at a temperature of approximately 1200-1500 degrees Farenheit (7). Exposure to this temperature would normally result in severe burns and neurological damage. Even without direct contact with a conducting element, this extreme heat would likely cause great pain and discomfort. Despite this, injuries are rare and most walkers report an extremely positive experience. Firewalkers are able to avoid injury to the feet and legs, and also do not report any pain. How could this be the case?

    There are two mysterious elements to the firewalk. Firstly, how does the walker manage to not burn the flesh of their feet? Secondly, how do they not feel pain? These are two distinct issues, although they are likely related (if the walker can avoid peripheral tissue damage, they may not experience pain). Many experts indicate that building up self-confidence is the most important aspect of the preparation (3). In the preparatory period, the firewalker achieves a state of focused relaxation, wherein blood flow to their feet is increased. The result is that heat can be rapidly whisked away and the flesh does not char.

    When a walker is not in the correct psychological state, peripheral capillaries are constricted and heat is unable to be properly whisked away from the foot soles (5). This happens when the walker is not confident; they tense up and thereby reduce blood flow to the periphery. It is important to know that people have occasionally been burned during firewalks. In these cases, there is nothing different about the fire itself. The occasional injury suggests that the key variable is this mental preparation, not the conductivity of the coals or the heat of the ash (5).

    Skeptics most frequently challenge the legitimacy of firewalking on the basics of thermodynamic physics. Heat is transferred from the coals to the feet via conduction. Both ash and the foot sole are poor conductors so the heat quickly dissipates and does not burn the flesh. Imagine a cake fresh out of the oven. Touching the cake will not burn you but touching the baking pan certainly will. The cake, like the ashen coals, is a poor conductor despite being very hot. (4) Tolly Burkan, founder of the Firewalking Institute of Research and Education (F.I.R.E.), refuted this argument by walking unburned across a heated metal grill (an excellent conductor), illustrating that the properties of the surface are largely irrelevant (4). He teaches that a successful firewalk is the product of your central nervous system changing its normal condition. As Burkan explains, “If you are relaxed with your decision [to walk on fire], you are in a certain biochemical state…If the body is tense, that is an indication of thought processes that will interfere with the mechanisms employed by the body to protect itself.” (3) In this sense, firewalkers are stimulating naturally-existent defense mechanisms to help absorb the heat.

    But this still does not explain how the walker avoids sustaining severe pain. Walkers say that the mental preparation is essential to ready the nervous system for the sensory onslaught. The mental preparation for the walk is generally divided into 4 Paths (1). These 4 Paths, (The Devotion, The Power of Will, The Power of Imagination, and The Clearance of Presence), help the walker to concentrate his/her energy on building confidence for a successful walk. The preparation is frequently described as “unidirectional,” because it is totally focused on reaching the other side unharmed. To this end, walkers imagine a dual nature for themselves, both picturing cold moss under their feet and also embracing the touch of coals. As a result, they are in a state of “neither-neither,” wherein they are not entirely in the present nor in the imagination (1). In this sense, they seem to be distancing themselves from the immediate sensory inputs.

    I would suggest that firewalking might be explained through some of the concepts we have been discussing. When someone gets nauseated in a car or on a boat, it is due to the incongruence of their nervous system expectations and the sensory input. In other words, corollary discharge signals setup an expectation for sensory input and then when they are not met, the person perceives that as discomfort. Perhaps the same mechanism explains how someone is able to turn off the sensation of pain. Pain is the non-correspondence of sensory input and corollary discharge signals. Therefore, if one could consciously alter these corollary discharge signals, they could theoretically turn off the normal pain sensation. Therefore, the secret of firewalking may lie in the alteration of corollary discharge signals by the i-function.

    If a walker could somehow adjust these expectations, it is theoretically possible that they could even undergo other painful events. Given two people with the same activity in sensory neurons, is it possible that they have different experiences? Yes, we know that sensory input is interpreted differently. Therefore, is it conceivable that because of other complicating factors, the nervous system interprets a certain set of inputs as pain in one person and not pain in another? This is also likely. All people do not gain pleasure from the same sensory inputs, and we do not feel pain in the same manner. To this end, we uniquely interpret sensory inputs.
   
    Perhaps this is what is going on during the period of mental preparation. In order to successfully cross the fire, one needs to go into a special state of mind. During this mental preparation, maybe the i-function is preparing the nervous system for a different interpretation of sensory inputs. Consider the example of long distance runners. These athletes are able to push themselves through great amounts of physical discomfort, and even describe a sensation of “runner’s high.” After running 10 miles, running does not get any easier or less uncomfortable. Rather, the nervous system may be adjusting the way it interprets sensory inputs. What is initially perceived as pain is later perceived as euphoric energy. This perception—the “I can run forever” feeling—appears similar to the experience of firewalkers, who report no pain and only a sense of enthusiastic confidence.

    On this same site ten years ago, Yun-Wen Shaw suggested that a biofeedback mechanism may also be involved. Specifically, if walkers can adjust their internal heat set point, then they would not feel the heat of the hot ash beneath them (2). Take the example of a fever. A sick person may feel cold and even shiver although their body is actually at an elevated temperature. Their thermal setpoint is adjusted upwards such that they do not feel warmth even though they may have a dramatically increased body temperature. If a walker could similarly readjust this setpoint, it is possible that they do not feel the overwhelming heat. Shaw’s hypothesis is somewhat similar to the one I suggested above; by conscious adaptation of the nervous system we are able to alter the interpretation of sensory inputs. I would be curious to know more about the feasibility of consciously adjusting thermal setpoints. It this were indeed possible, humans might theoretically be able to survive in various extreme environments.

    While the physics of firewalking have been thoroughly debated, the neurological aspects of this phenomenon are less clear. How is it that firewalkers can avoid burning their feet? Perhaps of more interest, how do they not feel pain? It is clear that we have control over the interpretations of our sensory inputs. Each one of us interprets these inputs in different ways. It is possible that firewalkers use mental preparation and focus to alter the normal interpretation of their sensory inputs so they do not feel pain from the fire. The extensive mental preparation may help them change the normal interpretation. Until I try it myself, I may not ever know for sure.



(1) http://www.kondor.de/shaman/coals.html

(2) /bb/neuro/neuro00/web2/Shaw.html

(3) http://www.firewalking.com/

(4) http://news.nationalgeographic.com/news/2005/09/0901_050901_firewalking.html

(5) http://www.corporatefirewalking.com/theory.html

(6) http://www.sparksdevelopment.com/history.html

(7) http://www.firewalker.co.uk/fire_walking/fire_walking.htm#Leidenfrost

(8) Neurobiology class notes/discussion, Professor Paul Grobstein, March/April 2010