1. What is the WBGT Index?

Definition: The Wet Bulb Globe Temperature (WBGT) is a measure of heat stress in direct sunlight, which takes into account temperature, humidity, wind speed, sun angle, and cloud cover.

Purpose: It's widely used in industrial, military, and athletic settings to assess heat stress risk and guide activity modifications.

2. How Does the Calculator Work?

The calculator uses the standard WBGT formula:

Where:

• \( T_w \) — Wet bulb temperature (°C)
• \( T_g \) — Globe temperature (°C)
• \( T_d \) — Dry bulb temperature (°C)

Explanation: The formula weights the wet bulb temperature most heavily (70%) as it best represents the body's ability to cool through sweat evaporation.

3. Importance of WBGT Measurement

Details: WBGT is more accurate than heat index for assessing heat stress risk in sunny, outdoor conditions. It's used to:

• Guide work/rest cycles in hot environments
• Modify athletic practices
• Prevent heat-related illnesses

4. Using the Calculator

Tips: Enter all three temperature measurements in °C. For indoor environments without solar load, a simplified formula (0.7T_w + 0.3T_g) may be used.

5. Frequently Asked Questions (FAQ)

Q1: What's a dangerous WBGT level?
A: Above 29°C is considered high risk, 32°C+ is extreme risk. However, risk varies by acclimatization and activity level.

Q2: How is WBGT different from heat index?
A: WBGT accounts for solar radiation and wind, making it better for outdoor settings, while heat index is for shade conditions.

Q3: Where can I get these temperature measurements?
A: Specialized WBGT meters are available, or you can use separate wet bulb, globe, and dry bulb thermometers.

Q4: What's the typical range for WBGT values?
A: Normally ranges from 15°C to 35°C, with values above 30°C indicating dangerous conditions for physical activity.

Q5: Are there different formulas for WBGT?
A: Yes, some variations exist for indoor environments or when certain measurements aren't available, but this is the standard outdoor formula.