• Heat Index: While WBGT is the preferred standard of measurement, the Heat index can be used as an alternative in the absence of WBGT monitoring equipment.
• Zone: Virginia is a Class 3 zone state.
• Unlimited Water Access: Coaches must provide unlimited access to water throughout practice. Rest breaks should focus on rehydration and rest only, with no activity.
• Cooling Measures: Have towels with ice for cooling of athletes as needed.
• Watch/monitor athletes carefully for necessary action.

Learn more about the VHSL WBGT guidelines here.

The heat index, or ‘feels like’ temperature combines air temperature and humidity, while Wet Bulb Globe Temperature (WBGT) offers a more holistic assessment of heat stress. WBGT considers air temperature, humidity, sun angle, cloud cover, and wind speed, providing a more realistic understanding of how the body responds to heat.

While the heat index only reflects skin sensation, WBGT tracks how efficient the body is at producing sweat, which is the main catalyst that cools the human body down. This makes it ideal for sports and outdoor activities. Perry Weather and the Virginia High School League recommend WBGT for heat stress management.

Coaches who initially preferred the heat index now find WBGT more reliable for making practice decisions. WBGT provides a fairer assessment of heat stress, allowing for more flexible training schedules.

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

Yes, adjustments have been made, but there are some constraints.

1. Limited Morning Practice Options
   “Our county doesn’t allow us to move practices to the mornings after teacher work week starts,” Chris explained. As schools start earlier in August, morning practices aren’t always an option.

2. Later Practice Times with Evening Adjustments
   To deal with high WBGT readings, “we’ve had to bump practices back a couple of times, moving them later in the evening.” This adjustment helps athletes avoid the hottest parts of the day while still getting their workouts in.

3. Using Facilities with Lights
   Thankfully, some facilities, like fields with turf and lights, make evening practices feasible. “We do have turf with lights, so that allows us to practice later in the day.”

4. Managing Heat Well This Year
   Despite a significant heat wave in Virginia, the team has managed the situation well. “Going through July, we were really worried about it, but August has been much more manageable.”

Many people confuse wet bulb temperature and wet bulb globe temperature (WBGT). These are two distinct measurements with different scales and implications for heat stress. People often shorten “Wet Bulb Globe Temperature” to just “Wet Bulb,” causing confusion between the two. It’s vital to use the correct scale for each measurement. 

• Wet Bulb Temperature: Think of wet bulb temperature (WBGT) as the lowest temperature that air can reach through water evaporation alone. It gives an indication of how quickly sweat can evaporate, which is important for cooling the body.
• WBGT: This measurement takes into account air temperature, humidity, solar radiation, and wind speed. It provides a more comprehensive assessment of heat stress, especially in outdoor settings.

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

There are several ways to measure Wet Bulb and Wet Bulb Globe Temperature (WBGT), and it’s important to use the right tools to ensure accurate readings. Here are the main methods:

1. Handheld Devices
   “Handhelds are one of the two most widely used and accepted tools,” especially in high school athletics. These portable devices allow you to take measurements on the go, making them convenient for coaches or athletic staff needing immediate data at practice fields or events.

2. Stationary Weather Units
   Another popular option is stationary weather stations. These are set up in a fixed location and continuously measure environmental factors to provide real-time WBGT data. “Stationary devices are also widely accepted,” particularly for monitoring large outdoor spaces, like football fields or tennis courts.

3. Apps & Other Methods
   While there are apps and more casual methods like “licking your finger and sticking it up in the air,” these are not reliable for measuring WBGT. Apps often use the “feels like” temperature, which can be misleading since it doesn’t account for all the environmental factors that affect the body during physical activity.

Stationary WBGT units like Perry Weather generally provide better accuracy, convenience, and reliability than a handheld device. Here are the key differences between them:

• Size and Sensitivity: Handheld devices are portable, but that comes with limitations. The black bulb (which measures heat radiation) on a handheld unit is significantly smaller, leading to faster spikes in temperature readings. Colin Perry explained, “That smaller surface area can heat up way faster than it should, which can cause spikes.”

• Accuracy and Setup Time: Handheld devices require time to acclimate. “You need to bring it out 30 minutes to an hour before practice,” Colin noted. In contrast, stationary units don’t need setup time and provide continuous, real-time readings.

• Consistent Readings: Stationary units offer more reliable data because they stay in one place and are shielded from direct sunlight. Chris Serafin shared that their county started relying on Perry Weather’s stationary units: “We’ve been so accurate with Perry Weather devices that we’ve moved away from handheld devices.”

• Convenience and Alerts: Stationary units can automatically sync with alerting systems, notifying staff instantly when thresholds are reached. Handheld devices require manual monitoring and communication, which can be time-consuming.

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

WBGT is a holistic measurement, and studies show that temperature readings across different surfaces tend to balance out when measured correctly.

“WBGT doesn’t specify that it needs to be measured on specific surfaces,” says Colin Perry, Perry Weather’s CEO. Studies by Dr. Grundstein at the University of Georgia found that whether you’re on grass, turf, or composite, differences in WBGT readings were “negligible.” Although turf may have slightly higher temperatures and lower humidity than grass, the differences balance out due to the multi-variable nature of WBGT.

“At 3 ft above the surface, the temperature and humidity became the exact same,” Colin explains. Air mixes effectively at waist height, making the surface differences insignificant. According to Chris Serafin, variations in wind exposure across different parts of the campus make a larger difference than the surface itself. “Wind is a way bigger factor. I haven’t noticed much of a difference between our turf and grass fields.” In fact, grass can give higher readings in the morning due to dew evaporation.

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

Managing fluctuating WBGT (Wet Bulb Globe Temperature) readings can be challenging, but here’s a practical approach to ensure safety while keeping practices efficient:

1. Adopt a Conservative Approach
   When faced with shifting WBGT zones, taking a conservative stance is crucial. “We’re pretty conservative with this,” says Chris Serafin. “Whenever we hit the red zone, we go right into it.” This approach prioritizes safety, minimizing the risk of heat-related issues.

2. Avoid Frequent Re-evaluations
   To avoid unnecessarily truncating practices, Chris advises against frequent re-evaluations of the WBGT readings. “We have made a policy that we do not re-evaluate until after five o’clock,” Chris explains. This policy helps prevent constant disruptions and allows for a more stable decision-making process.

3. Flexibility in Practice Scheduling
   Coaches are encouraged to adjust practice times if needed. “We let coaches know they can change their practice times within 24 hours,” Chris notes. This flexibility helps accommodate changes in the weather while keeping parents informed and satisfied with the adjustments.

Previously, logging WBGT readings involved a cumbersome process. “We would text every 15 minutes and use a pocket tablet to write everything down,” Chris explained. This data was then entered into a Google form and submitted to the county. “It was a lot more work for us than what we’re doing now,”. Additionally, inconsistencies in readings across different areas were a problem.

Switching to Perry Weather
Switching to Perry Weather has streamlined the process significantly. The transition from handheld devices to Perry Weather’s WBGT system has improved accuracy and efficiency. “The readings are a lot more similar now than they used to be,” the speaker said.

The handheld devices previously used showed significant variability. A client found a three-degree difference in WBGT readings between different parts of the field, which could lead to inconsistent safety measures. Perry Weather’s system ensures more reliable and consistent readings.

According to Chris, “we’ve created specific alerts that correspond to the Virginia High School League (VHSL) heat index guidelines. When these thresholds are reached, athletic trainers receive push notifications.”

Stafford County Public Schools use a combination of sirens, flashing lights, and PA announcements to alert everyone on campus about potential heat-related risks.

The system allows us to send custom messages, such as “practice canceled due to extreme heat” or “reduce equipment and take water breaks.” The Perry Weather system includes a camera and sensor that work independently. Even if the camera goes offline, the system continues to provide accurate readings from the on-site weather station.

Chris notes that, “Perry Weather has significantly improved our ability to manage practice safety during hot weather.”

Tracking weather conditions on-site is crucial for accurate and timely information. Here’s why:

1. Accuracy of External Sources
   “When you pull up weather data on your phone, it’s often an estimation rather than precise information,” the speaker notes. Phone apps typically rely on data from the nearest airport, which may be miles away from your location. This can lead to significant inaccuracies, as these estimates can either overestimate or underestimate actual conditions.

2. Distance and Delay Issues
   Data from external sources like airports can be problematic. “The nearest weather station might be 30 to 40 miles away and the data only updates every 60 minutes,” which means you could be working with information that’s not only outdated but also from a location far from where you are.

3. Real-Time Monitoring Needs
   For accurate weather monitoring, especially on a large campus, “you need to track conditions in real-time.” Factors like cloud cover and wind speed, which significantly impact conditions, change rapidly. An on-site weather station provides immediate, localized data, allowing you to make timely decisions based on current conditions rather than outdated or distant estimates.

4. Safety and Effectiveness
   On-site monitoring ensures safety and effectiveness, particularly in managing outdoor activities and events. “With variables like wet bulb globe temperature that are sensitive to local conditions, on-site measurement is essential.”

When it comes to managing middle school practices during heat waves, here’s how we’re handling the situation:

1. Relying on Nearby High Schools
   “Our middle schools use the readings from the nearest high school because we don’t have a certified athletic trainer at every middle school,” explained Chris. This is possible since many middle and high schools are located close to each other, sometimes even on the same campus.

2. Monitoring Heat Across Schools
   We ensure safety by shutting down practices if any school in the county reaches a WBGT of 90 degrees. “If anybody in the county hits that 90 degrees, we’re being sensitive to that and shutting everything down.”

3. Centralized Decision-Making
   With classes and other activities happening, “our central office is now able to make decisions by looking at readings from all the schools,” including nearby facilities. This centralized approach helps in making informed decisions promptly.

4. Effective Communication
   The system in place allows for sharing updates with other schools and coaches. “I was able to give my coach a heads up about potential black flags, so we’re not surprised when we get there.”

Perry Weather has enhanced the working relationship between athletic trainers and coaches, especially in managing heat-related restrictions. Here are some key takeaways:

1. Enhanced Communication
   “I’ve always had a pretty good relationship with our coaches,” noted Chris. With Perry Weather, this relationship has become even smoother. The integration of accurate weather data has removed the need for subjective decision-making about weather conditions.
2. Eliminating Subjectivity
   He highlighted a common issue: “The jokes about not seeing lightning or turning a blind eye to weather conditions are completely gone now.” With Perry Weather’s precise and reliable data, decisions are based on concrete information, eliminating the uncertainty and guesswork that sometimes led to tension.
3. Focus on Core Responsibilities
   The use of Perry Weather has allowed trainers to focus on their primary roles, such as “getting people back on the field, doing rehabs, doing evaluations.” By not having to double as a “weatherman,” trainers can concentrate on providing care and support to athletes.
4. Improved Morale and Perception
   A notable improvement in team dynamics is reflected in an anecdote from Virginia’s Prince William County. An athletic trainer, once known as the “Grim Reaper” due to frequent enforcement of heat restrictions, now enjoys a better reputation. “Not anymore,” she said with a laugh, highlighting the positive change in how her role is perceived.