Webinar + FAQs: Understanding the New Iowa IHSAA WBGT Guidelines

• Wet bulb globe temperature is a holistic measure that considers more environmental variables that are indicative of how the human body responds to heat stress. It takes into account multiple factors, including:
  • Sun angle
  • Wind speed
  • Humidity
  • Cloud cover
  • Air temperature

  On the other hand, the heat index is designed to be used in an indoor setting because it doesn’t factor in the wind or sun angle. It takes into account the air temperature and humidity to gauge what the temperature “feels like” to the human body.

  Why is WBGT a better indicator of heat stress?

  According to James, “the wet bulb globe temperature as opposed to the heat index, gives us a more accurate reading as to how the student athletes are feeling, and what’s going on out there on the turf.” This is crucial for preventing heat-related illnesses, particularly in student-athletes.

  • More variables: WBGT accounts for additional factors that directly affect how the human body responds to heat.
  • Accuracy: WBGT provides a more accurate assessment of the perceived heat and risk of heat-related illness.
  • Real-world conditions: WBGT is more relevant to outdoor activities where sun angle and wind play significant roles.

  Brittany states, “If that sun is just beating down on you, there’s no cloud cover, you’re baking. WBGT captures this, but the heat index does not.”

  As a result, WBGT should be the school’s first choice for heat stress monitoring.

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

Although handheld weather devices offer a quick, portable, and convenient way to measure heat stress, stationary weather stations are significantly more accurate and offer much more reliable weather data.

As Brittany pointed out, relying on handheld devices can be time-consuming and labor-intensive.

“I would have to go to the field earlier during the day, take a temperature reading with a handheld device, then leave and then come back, do it again several times throughout the day and the handheld still wouldn’t indicate what might be practice time later that day.”

In contrast, stationary WBGT stations, like Perry Weather, offer automated and consistent monitoring from a fixed location.

These systems not only reduce the manual workload but also provide real-time data and alerts that can be disseminated across the entire school district.

James emphasized how this consistency is crucial in large districts where conditions can vary significantly between different schools.

With a stationary system, all coaches and trainers receive the same data simultaneously, enabling more informed and unified decisions regarding practice schedules and safety protocols.

Learn more about the differences between handheld devices and stationary weather stations here.

This is a common question, especially for campuses that have multiple types of surfaces like grass, turf, or concrete. It’s true that at ground level, turf is often hotter than grass—especially on a sunny day. As James pointed out, “Turf is gonna be hotter 99.9% of the time.” However, when the weather station is placed at shoulder level, it closely mimics how the human body experiences heat.

However, in a study conducted by Dr. Grundstein and Dr. Casa at the University of Georgia, they found that a few feet above the ground, where WBGT sensors are positioned, the differences in surface type don’t significantly affect the WBGT readings.

The differences in WBGT readings are minimal and there’s no need for significant adjustments based on whether the activity is on turf or grass. You can follow the same heat safety protocols regardless of the surface.

Learn more about the impact of different surfaces on WBGT here.

In a school district, whether large or small, having a unified weather safety and operations tool is crucial for ensuring the safety of students and staff. Here’s a breakdown of why this approach is so important:

Consistency Across the District:

• A single weather monitoring platform across all campuses ensures consistency in weather data across the district. As James notes, “A unified weather safety plan ensures everyone is reacting to the same readings and making consistent decisions.”

Simplified Operations:

• James highlights, “Perry Weather fits into our overall operations plan, making it easier to handle weather-related decisions like water breaks during events.”

Improved Safety Management:

• A unified weather monitoring platform helps coordinate safety measures more effectively. Brittany recalls managing water breaks during a soccer match, emphasizing the importance of a unified approach for consistent safety.

Prevention of Discrepancies:

• “A unified tool eliminates inconsistencies and ensures everyone is on the same page.” Brittany notes.

Efficient Communication:

• A unified approach enhances coordination between athletic trainers, coaches, and administrators. “It’s easier to coordinate with a single tool, ensuring alignment with the same policies.”

Compliance with Regulations:

• Brittany emphasizes, “It helps comply with state requirements and raises awareness about preventable deaths in athletics.”

Peace of Mind:

• Provides reassurance that safety measures are consistent. James reflects, “It reduces the stress of making last-minute decisions.”

When WBGT readings fluctuate during a workout, the safest course of action is to stick with the initial risk zone established at the start of practice. This consistent and conservative approach helps protect athletes from the dangers of fluctuating heat stress, ensuring their well-being throughout the workout.

Here’s how you can handle these situations to ensure athlete safety:

1. Stick to the Initial Zone:

• Scenario: Imagine you start a football practice in the orange zone (moderate risk), and midway through practice, the WBGT reading spikes into the red zone (high risk) due to sudden sunlight. Then, clouds return, bringing the reading back to orange.
• District Policy: In this scenario, the best practice is to stick to the initial zone where the workout began. This conservative approach ensures that athletes are not exposed to additional heat stress.

2. Avoid Fluctuating In and Out of Zones:

• Consistency: According to district practices, once you’ve established the risk zone at the beginning of practice, maintain that level. For example, if you start in orange and the reading briefly dips to yellow (low risk) due to temporary cloud cover, continue following the orange zone guidelines.
• This approach prevents confusion and ensures that athletes aren’t exposed to fluctuating risks. As Justin mentioned, “We don’t want to revert back to a green zone because now it’s cooled off, only to have it jump back to orange 10 minutes later. It’s about keeping kids safe and using our best judgment.”

3. Responding to Higher Risk Zones:

• If WBGT readings rise into a higher risk zone (e.g., from orange to red), it’s crucial to adjust your practice immediately. This may mean shortening the practice or increasing rest breaks.
• Example: If your practice moves into the red zone with only 15 minutes left, you might allow the practice to finish, but avoid extending it. “We’re probably going to let you finish,” a coach noted, “but we’re not going to let you go for another hour in that zone after they’ve already been in orange.”

4. Prioritize Safety and Consistency:

• Conservative Approach: The underlying theme is to prioritize safety by adopting the most conservative approach.
• As one speaker put it, “Just take the most conservative approach and be consistent. If you start fluctuating, you leave room for interpretation and potential arguments, which can compromise safety.”