Wet Bulb Globe Temperature

The Wet Bulb Globe Temperature (WBGT) is a composite temperature used to estimate the effect of temperature, humidity, wind speed (wind chill), and visible and infrared radiation (usually sunlight) on humans. It is used by industrial hygienists, athletes, and the military to determine appropriate exposure levels to high temperatures. It is derived from the following formula:

Where

  • Tw = Natural wet-bulb temperature (combined with dry-bulb temperature indicates humidity)
  • Tg = Globe thermometer temperature (measured with a globe thermometer, also known as a black globe thermometer)
  • Td = Dry-bulb temperature (actual air temperature)
  • Temperatures may be in either Celsius or Fahrenheit

Indoors, or when solar radiation is negligible, the following formula is often used:

The WBGT index was developed in 1956 by the United States Marine Corps at Parris Island to reduce heat stress injuries in recruits; it has been revised several times.

Read more about Wet Bulb Globe Temperature:  Uses

Famous quotes containing the words wet, bulb, globe and/or temperature:

    “Here in the centre stands the glass. Light
    Is the lion that comes down to drink. There
    And in that state, the glass is a pool.
    Ruddy are his eyes and ruddy are his claws
    When light comes down to wet his frothy jaws”
    —Wallace Stevens (1879–1955)

    “... until the shopkeeper plants his boot in our eyes,
    and unties our bone and is finished with the case,
    and turns to the next customer, forgetting our face
    or how we knelt at the yellow bulb with sighs
    like moth wings for a short while in a small place.”
    —Anne Sexton (1928–1974)

    “The murmurs of many a famous river on the other side of the globe reach even to us here, as to more distant dwellers on its banks; many a poet’s stream, floating the helms and shields of heroes on its bosom.”
    —Henry David Thoreau (1817–1862)

    “The bourgeois treasures nothing more highly than the self.... And so at the cost of intensity he achieves his own preservation and security. His harvest is a quiet mind which he prefers to being possessed by God, as he prefers comfort to pleasure, convenience to liberty, and a pleasant temperature to that deathly inner consuming fire.”
    —Hermann Hesse (1877–1962)