Navigating the New NMAA Heat Stress Policies: Webinar + FAQs

• Schools Must Obtain WBGT or Heat Index Readings: Schools must measure either WBGT or heat index at practice and competition sites to assess heat conditions.
• WBGT is the Preferred Measurement: Wet bulb globe temperature is the preferred measurement, however, whichever measurement (WBGT or heat index) reaches the heat stress threshold first determines the heat category and subsequent guidelines.
• For instance, if the heat index surpasses its limit before the WBGT, the heat category is based on the heat index. Conversely, if the WBGT reaches its threshold first, it dictates the heat category.
• Emergency Action Plans: Schools must have emergency action plans, including access to cold-water immersion tubs for rapid cooling in case of exertional heat stress and heat-related emergencies.
• Unrestricted Hydration: Athletes must have constant access to water.

NMAA’s new heat stress guidelines utilize both Wet Bulb Globe Temperature (WBGT) and Heat Index to assess outdoor conditions and protect student-athletes.

1. Heat Index: The Heat Index is a measurement that combines only two environmental factors (air temperature and humidity) to estimate what the temperature “feels like”. “Feels like” temperature tells you what the human body is feeling like the temperature outside is.
   Eg: On a day when the temperature is 85°F with high humidity, the Heat Index might suggest it feels more like 95°F, indicating a higher perceived temperature due to moisture in the air.
2. Wet Bulb Globe Temperature (WBGT): WBGT is a more holistic way to measure how the body is interacting with the outside environment. The WBGT considers multiple environmental factors (air temperature, humidity, sun angle, cloud cover, wind speed) to assess how the body interacts with the outside environment. It takes into account how effective the body is at producing sweat, which is the main catalyst to cool yourself down.
   Eg: On a partly cloudy day with a light breeze, even if the temperature is high, the WBGT might indicate a lower risk for heat stress due to the cooling effect of the wind and cloud cover.

Many athletic organizations, such as the NMAA, use both WBGT and Heat Index in their safety guidelines. In practice, if the WBGT is lower but the Heat Index is higher, safety protocols might still limit practice duration or require additional breaks, as was the case when the WBGT was around 80°F (green zone) but the Heat Index was 98-99°F, triggering stricter safety measures.

For safety, especially in athletic settings, it’s crucial to consider both, often adhering to the stricter of the two measurements.

The NMAA mandates real-time, onsite temperature monitoring to provide accurate and immediate readings, especially in areas with changing weather conditions. Colin emphasizes that this on-the-spot monitoring is crucial, particularly in diverse regions of New Mexico, since local weather apps typically rely on data from the nearest airport weather station, which only updates once an hour.

Here are some of the key differences between handheld devices and stationary weather stations:

Handheld WBGT Devices: While handheld WBGT devices offer portability, they come with challenges such as calibration time, battery management, and potential data inaccuracies.

• Portability: Handheld devices are small and often mounted on a tripod, making them portable and easy to set up in different locations.

• Calibration Time and Recalibration: These devices require time to acclimate when moved from indoors to outdoors, typically taking 20 to 30 minutes to provide valid readings.
• Lack of Radiation Shield: Many handheld devices lack a radiation shield, leading to erroneous data due to direct sunlight exposure, causing temperature spikes.
• Smaller Black Bulb: The smaller black bulb in handheld devices heats up and cools down faster, resulting in more erratic readings compared to standardized sensors.
• Lack of Data Logging Capability: Handheld devices often struggle with consistent data logging due to potential timeouts and connection issues, making it difficult to track historical data accurately.

Justin Segotta also notes that setting up handheld devices is challenging due to the need to manage battery life, recalibration, and potential timeouts, which often lead to disruptions in data collection.

Stationary Weather Stations: Stationary weather stations, on the other hand, provide reliable, continuous monitoring with better data accuracy and ease of use, making them a more effective solution for ensuring athlete safety during outdoor activities.

• Continuous Monitoring: Stationary devices are installed permanently, providing continuous real-time monitoring without the need for acclimation or frequent calibration.
• Radiation Shield: These stations typically have a radiation shield, ensuring accurate temperature and humidity readings.
• Standardized Black Bulb: Stationary weather stations also use a standardized black bulb as per ISO standards, leading to more stable and reliable data that corresponds accurately to how the body heats and cools.
• Reliability: Stationary weather stations eliminate the need to manually set up equipment daily and avoid issues like battery failure or device timeouts.
• Remote Access: Users can access real-time data remotely from multiple locations (e.g., different sports fields), allowing for better-informed decisions regarding practice schedules.
• Data Logging Capabilities: These stations provide uninterrupted logging of weather data, enabling users to review historical trends over days or weeks. This helps coaches plan practices based on patterns and make necessary adjustments for future sessions.

If you’re looking for consistent, reliable data without much maintenance, a stationary weather station is likely your best bet. It offers seamless monitoring and better accuracy, making it a solid choice for ensuring athlete safety.

According to Justin, using a stationary weather station offers significant advantages over handheld WBGT devices on a day-to-day basis, making operations easier and more efficient. He notes, “The biggest thing is now coaches get those notifications. It’s just another thing you’re not having to worry about all the time. Most of it’s taken off your plate and handled for you.”

He also loves using the widget feature a lot. “Those widgets can be super powerful. I know we’ve got a couple customers of ours that even throw the lightning countdown timer up on the scoreboard so all the fans and everyone can see it or QR codes and stuff like that.”

1. Ease of Use: Stationary weather stations require minimal setup and are largely hands-off, providing continuous monitoring, unlike handheld devices that need regular calibration and manual operation.
2. Automated Alerts: Stationary stations send real-time notifications directly to coaches and staff, ensuring everyone stays informed, while handheld devices lack automated alert capabilities.
3. Widespread Communication: Data from stationary stations can be displayed on screens in key locations, such as athletic training rooms, enhancing accessibility and communication.
4. Campus Coverage: Stationary stations are ideal for large or spread-out campuses, allowing centralized monitoring without the need to move equipment.
5. Safety Management: By automating monitoring and communication, stationary weather stations reduce the workload on staff and improve overall safety management.
6. Consistent Monitoring: With features like real-time alerts and easy accessibility, stationary stations help ensure that weather conditions are consistently monitored, keeping athletes safer.

When discrepancies in readings occur, such as with lightning or temperature, the host school’s data and decisions take precedence. It’s important for the host school to communicate effectively with visiting teams and officials to ensure everyone is on the same page and understands the reasoning behind any safety-related decisions.

• The host school is responsible for monitoring temperature during the game.
• The athletic trainer, site admin, and officials work together to ensure safety.
• The host school’s decisions take precedence in case of discrepancies.
• Effective communication with visiting teams and officials is essential.
• Clear communication helps maintain a safe environment and manage disagreements.

Open communication is key to managing these situations smoothly. By keeping everyone informed, the host school can ensure a safe environment for all participants, even if there are initial disagreements.

The latest NMAA heat stress guidelines recommend using both wet bulb globe temperature and the heat index in conjunction with each other to ensure the safety of athletes during outdoor activities.

By monitoring both WBGT and Heat Index, you can adhere to the stricter guideline of the two. For example, if the Heat Index reaches a critical level before WBGT, you should follow the protocols based on the Heat Index, and vice versa.

Learn more about the differences between the heat index and wet bulb globe temperature here.

Ideally, weather stations should be placed at eye level, about 2 to 3 meters (6.5 to 10 feet) above the surface. This height provides a good balance between accurate temperature, humidity, and wind speed readings. However, that may not be feasible in many cases.

At Perry Weather, we’ve placed the weather stations on top of field houses, press boxes on a light pole of a stadium, and many more variations. The only difference we’ve seen in the measurements is the wind speed, as the wind speed increases with height.

However, Perry Weather automatically corrects the wind speed for WBGT calculations, adjusting readings from higher placements down to a standard 2-meter level using a common meteorological equation.

Colin also notes that the Texas A&M Atmospheric Sciences department is conducting a study comparing handheld devices, Perry Weather stations, and other control devices. Their findings have shown that the readings from Perry Weather stations placed at a building height are nearly identical to those at field level once the wind speed correction is applied.