Use of the Wet Bulb Globe Temperature (WBGT) index to quantify environmental heat loads during three-day-event competitions.

The research explores the use of the Wet Bulb Globe Temperature (WBGT) index as a means to measure the environmental heat load affecting both horse and rider during three-day-event competitions. Previously used measures, such as the Comfort Index, have been deemed deficient as they overlook elements like solar heat load.

Background and Motivations

• The environment in top-level international 3-day-event competitions can be hot and stressful, affecting the wellbeing of the horse and rider. Quantifying the heat load in such environments to reflect the impact of weather has been a challenge.
• The ‘Comfort Index’, which calculates using ambient temperature and relative humidity, has been previously used. However, it failed to account for the solar heat load, a significant factor of environmental heat load.
• The Fédération Equestre Internationale (FEI) initiative aimed at assessing the ability of horses to compete under thermally stressful conditions, such as anticipated for the 1996 Olympic Games, necessitates an objective way to measure effective heat load.
• Consideration of microclimatic conditions, duration and severity of the competition, ground conditions, fitness and capability of horse and riders, is essential in a well-rounded assessment of thermal stresses.

Introducing the Wet Bulb Globe Temperature (WBGT) Index

• The research proposes the use of the WBGT Index, which offers a more holistic measure of the effective heat load experienced by the horse and rider.
• Unlike the Comfort Index, the WBGT Index takes into account elements like wind strength and radiation along with ambient temperature and humidity.
• This index provides valuable insights for course designers and officials to plan and manage events, ensuring due consideration for local environmental conditions.