Keeping our cool: Safeguarding students and staff against summer heat risks

By Dave Kyllo, Kyllo Consulting

As summer is set to officially begin, Minnesota school leaders are encouraged to consider summer heat-related risks as their school district operations extend into the hottest months of the year. Whether running summer school, hosting athletic camps, or conducting essential building maintenance, school leaders often face a rising challenge: extreme heat.

To protect your school district community, it is vital to understand the physiological impacts of heat and recognize the distinct risks associated with summer operations.

Understanding Heat Illness: From Mild Stress to Life-Threatening Emergency

Heat-related illnesses typically exist on a spectrum and may rapidly escalate if left unchecked and unaddressed. Understanding the relative severity continuum of each condition is the first line of defense for educators and staff, in general:

Heat Stress [Mild] ─> Heat Exhaustion [Moderate/High] ─> Heat Stroke [Extreme/Emergency]

1. Heat Stress (Mild Severity)

This is the body’s initial reaction to overheating. It manifests as discomfort, fatigue, irritability, and minor physical symptoms like heat rash or muscle cramps. While not an immediate medical emergency, heat stress is a critical warning sign that the body is working overtime to cool itself down and a condition that should not be ignored.

2. Heat Exhaustion (Moderate to High Severity)

When the body loses excessive water and salt through heavy sweating, heat exhaustion sets in. Symptoms include dizziness, headache, nausea, weakness, and cool, clammy skin. A person experiencing heat exhaustion must be moved to a cool area and given fluids immediately. If untreated, it can quickly progress to heat stroke.

3. Heat Stroke (Extreme Severity/Medical Emergency)

Heat stroke is a life-threatening failure of the body’s temperature-regulating system, where the core body temperature spikes rapidly (often above 103°F or 39.4°C). The hallmark signs are an altered mental state (e.g., confusion, slurred speech, or loss of consciousness), a rapid pulse, and hot, red, dry, or heavily sweating skin. Heat stroke requires immediate emergency medical attention (i.e., call 911); failure to treat it promptly can result in permanent organ damage or death.

5 Heat-Related Risks in Summer School Operations

Operating a school district in extreme summer heat introduces specific vulnerabilities that go far beyond standard classroom management.

1. Outdated or Overburdened HVAC Infrastructure

Many school buildings, especially older facilities, were designed with the assumption that they would be vacant during July and August. Substandard or malfunctioning air conditioning systems can turn classrooms into dangerous heat traps and potentially accelerate heat stress among occupants.

2. Vulnerable Student Populations

Children’s bodies thermoregulate less efficiently than adults – generally, they tend to sweat less and adapt to heat more slowly. Furthermore, students with pre-existing conditions (such as asthma, obesity, or diabetes), as well as those taking certain medications, often face a significantly higher risk of severe heat illness.

3. High-Risk Athletic and Extracurricular Activities

Summer football practices, marching band rehearsals, and outdoor recess place intense physical demands on students during peak sunlight hours. Without strict oversight, the combination of high humidity, direct sun, and heavy exertion may become a primary catalyst for exertional heat stroke.

4. Hazard Exposures for Facilities and Custodial Staff

Students are not the only ones at risk. Groundskeepers, maintenance crews, and custodial staff often work in non-air-conditioned spaces (like boiler rooms or attics) or outdoors performing heavy labor. These workers face prolonged exposure to extreme heat, often while wearing heavy protective gear.

5. Microclimates on Playgrounds and Astroturf

School grounds frequently feature “heat islands.” Blacktop parking lots, dark rubber playground mats, and synthetic turf fields absorb and radiate heat. On a 90°F day, the surface temperature of artificial surfaces can exceed 150°F, creating a localized microclimate capable of causing contact burns and rapid dehydration.

Key Strategies to Mitigate Summer Heat Risks

School districts can proactively safeguard their campuses by implementing three systematic changes (among others):

1. Establish a “Heat Acclimatization” and Scheduling Protocol

The human body needs time to adapt to high temperatures. Districts should mandate a 7-to-14-day heat acclimatization period for athletes and outdoor workers, gradually increasing their exposure and workload.

• Suggested Action Item: Shift outdoor activities, sports practices, and heavy maintenance work to the early morning hours, and strictly avoid peak heat periods (usually between 10 a.m. and 4 p.m.).

2. Implement WBGT-Based Activity Modifications

Relying solely on a standard thermometer or a basic heat index chart is arguably no longer sufficient for monitoring heat exposure levels. School districts should consider utilizing a Wet Bulb Globe Temperature (WBGT) device to measure heat stress in direct sunlight. WBGT accounts for temperature, humidity, wind speed, sun angle, and cloud cover.

• Suggested Action Item: Create a standardized district matrix that dictates clear actions based on WBGT readings (e.g., mandatory shade breaks every 15 minutes, canceling outdoor activities, or moving practices indoors).

3. Create “Cooling Zones” and Comprehensive Staff Training

Preparation can mean the difference between a minor incident and a tragedy. Districts should equip campuses with designated, easily accessible cooling zones supplied with ice, water, and shade.

• Suggested Action Item: Train all educators, coaches, and support staff to recognize the early signs of heat exhaustion and heat stroke. Ensure that high-risk areas (like athletic fields) are equipped with cold-water immersion tubs, which remain the single most effective tool for rapidly lowering core body temperature during a heat stroke emergency before paramedics arrive.

By treating extreme heat as a predictable, manageable hazard rather than an unpredictable inconvenience, school districts can help ensure that summer learning and other activities remain safe, productive, and secure for everyone.