Firewalking is the act of walking barefoot over a bed of hot embers or stones. It has been practiced by many people and cultures in many parts of the world, with the earliest known reference dating from Iron Age India c. 1200 BCE. It is often used as a rite of passage, as a test of strength and courage, and in religion as a test of faith.
Modern physics has explained the phenomenon, concluding that the foot does not touch the hot surface long enough to burn and that embers are poor conductors of heat.
Walking on fire has existed for several thousand years, with records dating back to 1200 BCE.[unreliable source?] Cultures across the globe use firewalking for rites of healing, initiation, and faith.
Firewalking is also practiced by:
Social theorists have long argued that the performance of intensely arousing collective events such as firewalking persists because it serves some basic socialising function, such as social cohesion, team building, and so on. Émile Durkheim attributed this effect to the theorized notion of collective effervescence, whereby collective arousal results in a feeling of togetherness and assimilation. A scientific study conducted during a fire-walking ritual at the village of San Pedro Manrique, Spain, showed synchronized heart rate rhythms between performers of the firewalk and non-performing spectators. Notably, levels of synchronicity also depended on social proximity. This research suggests that there is a physiological foundation for collective religious rituals, through the alignment of emotional states, which strengthens group dynamics and forges a common identity amongst participants.
Per the second law of thermodynamics, when two bodies of different temperatures meet, the hotter body will cool off, and the cooler body will heat up, until they are separated or until they meet at a temperature in between. What that temperature is, and how quickly it is reached, depends on the thermodynamic properties of the two bodies. The important properties are temperature, density, specific heat capacity, and thermal conductivity.
The square root of the product of thermal conductivity, density, and specific heat capacity is called thermal effusivity, and tells how much heat energy the body absorbs or releases in a certain amount of time per unit area when its surface is at a certain temperature. Since the heat taken in by the cooler body must be the same as the heat given by the hotter one, the surface temperature must lie closer to the temperature of the body with the greater thermal effusivity. The bodies in question here are human feet (which mainly consist of water) and burning coals.
Due to these properties, David Willey, professor of physics at the University of Pittsburgh at Johnstown, points out that firewalking is explainable in terms of basic physics and is neither supernatural nor paranormal. Willey notes that most fire-walks occur on coals that measure about 1,000 °F (538 °C), but he once recorded someone walking on 1,800 °F (980 °C) coals.
Additionally, Jearl Walker has postulated that walking over hot coals with wet feet may insulate the feet due to the Leidenfrost effect.
A myth that persists is that safe firewalking requires the aid of a supernatural force, strong faith, or on an individual's ability to focus on "mind over matter".
Since the 20th century, this practice is often used in corporate and team-building seminars and self-help workshops as a confidence-building exercise.