Severe weather can occur in many different forms, and each type presents unique safety risks. Thunderstorms are one of the most common weather hazards during outdoor activities. They can produce dangerous conditions such as lightning, strong winds, hail, tornadoes, and heavy rainfall.

The National Weather Service (n.d.a) defines a severe thunderstorm as a storm that produces winds of at least 58 mph (50 knots), hail that is at least 1 inch in diameter, and/or a tornado. When storms are expected to reach these thresholds, a Severe Thunderstorm Warning may be issued to alert the public that hazardous weather is occurring or about to occur. However, storms do not need to meet official “severe” criteria to still pose risks. Some thunderstorms produce strong winds, lightning, or small hail that can still threaten outdoor activities and your safety and that of your campers.

In addition to wind and hail, thunderstorms can also produce heavy rainfall that leads to flooding. Flood Warnings or Flash Flood Warnings may be issued depending on how quickly water levels will rise and how much rain has already fallen.

Warnings, Watches, and Special Weather Statements

Understanding weather alerts is critical when making safety decisions during outdoor activities. The National Weather Service and Storm Prediction Center use several types of alerts to communicate the level of severe weather risk:

Warning. A Severe Thunderstorm Warning is issued when a thunderstorm is actively producing dangerous conditions such as hail larger than 1 inch in diameter, winds greater than 58 mph, or a tornado. This means severe weather is occurring or about to occur in the warned area. If you are located within a warning area, you should take action immediately by moving campers to a safe shelter and following your camp’s severe weather safety procedures.

Watch. The Storm Prediction Center issues a Severe Thunderstorm Watch or Tornado Watch when conditions are favorable for severe storms to develop. A watch does not mean that severe weather is currently happening, but it indicates that storms capable of becoming severe may form. During a watch, you should remain weather aware, monitor forecasts, and be prepared to act quickly if storms develop.

Special Weather Statement. The National Weather Service issues a Special Weather Statement when storms may produce hazardous conditions but do not meet official severe criteria. These storms may still produce gusty winds, small hail, or heavy rainfall. While these storms are not technically classified as severe, they can still pose safety risks, especially for outdoor groups.

Tornado Safety

Tornadoes are violent, rotating columns of air that extend from the base of a thunderstorm to the ground. Wind speeds inside a tornado can range from around 65 mph to more than 200 mph, making them one of the most destructive weather hazards. If you are in a tornado warning area or see a tornado approaching, you should take shelter immediately. The movement of tornadoes can be unpredictable, so you should never attempt to outrun, outdrive, or go around a tornado. Instead, find the nearest safe shelter and remain there until the threat has passed.

The safest place to take shelter during a tornado is in a storm cellar or basement. If a below-ground shelter is not available, move to a small, interior, windowless room on the lowest level of a sturdy building. Bathrooms, hallways, and small closets often provide the best protection, because they have additional interior walls. While sheltering, crouch low and cover your head and neck with your arms to protect yourself from flying debris.

If no buildings or shelters are nearby, lie flat in a low area such as a ditch or depression in the ground and cover your head. Stay as far away as possible from trees, vehicles, and power lines, which may fall or become airborne during strong winds.

Avoid taking shelter under highway overpasses or bridges, inside portable buildings, on upper levels of buildings, in large open rooms such as gyms or cafeterias, or in vehicles. These areas offer little protection and may actually increase the danger during a tornado (National Weather Service, n.d.b).

Lightning Safety

Lightning is not classified as severe weather, but it still poses a significant safety risk. Thunderstorms can produce several different types of lightning. Cloud-to-ground lightning presents the greatest danger to people, because it directly strikes the ground. However, cloud-to-cloud lightning should also be taken seriously, as it often indicates that cloud-to-ground strikes are possible. According to the 2025 Annual Lightning Report by Vaisala Xweather, approximately 250 million lightning strikes were detected across the United States in 2025.

If lightning is detected within 10 miles of your location, you should seek shelter indoors immediately. Trees, awnings, covered patios, and picnic shelters do not provide adequate protection from lightning. The safest place to be during a lightning threat is inside a fully enclosed building or a hard-topped vehicle.

It is also important to remember that lightning is not directional. Even if a thunderstorm appears to be moving away from your location, lightning can still strike many miles away from the storm in any direction. Because of this, you should never assume you are safe simply because the rain has stopped or the storm appears to be leaving the area.

A common safety guideline used by many organizations is the 10-mile, 30-minute rule. When lightning is detected within 10 miles, outdoor activities should stop, you should move to shelter, and activities should not resume until at least 30 minutes after the last lightning strike within a 10-mile radius. Following this rule helps ensure the storm has moved far enough away to reduce the risk of lightning strikes.

Action Plans

Having a clear action plan before storms move into the area is one of the most important parts of severe weather safety. Make sure you are aware of and understand the weather risks for the day, and know what steps to take if conditions begin to deteriorate. Checking the most up-to-date weather forecast before outdoor activities begin can help you anticipate potential hazards and prepare accordingly.

You should also know where the nearest safe shelters are located and how to quickly move campers to those locations if severe weather develops. Buildings that provide protection from lightning, strong winds, and hail should be identified ahead of time so that your group can reach them quickly. Practicing these plans before severe weather occurs can help ensure that everyone knows what to do and where to go.

If a flood warning is issued, groups should immediately move to higher ground and avoid low-lying areas such as creeks, drainage channels, and flood-prone fields. Flooding can occur quickly during heavy rainfall, so it is important to react early and follow established safety procedures.

Planning ahead, staying informed about weather conditions, and responding quickly when alerts are issued will help keep you and everyone in your charge safe during severe weather.

Understanding Heat Illness and Identifying Warning Signs

Stormy weather isn’t the only weather-related risk at camp. Have you ever had a sensation where you have been outside in the heat either playing a sport, walking with friends, or simply relaxing on the beach, and you began to feel dizzy, tired, or maybe lightheaded? Hot weather can be an awesome time for outdoor activity, but this environment can also cause people to start feeling sick or ill. Why is that? What is happening to the body that causes someone to start feeling these symptoms? The answer might be heat illness.

Heat illness occurs when body temperature rises abnormally high, which is also known as hyperthermia. Body temperature typically regulates to between 97°F and 99°F, and it naturally fluctuates during the day. Hyperthermia can happen in many ways. If it’s very hot outside the body can absorb heat from the environment. The body also produces heat when someone plays or exercises outside because the process of moving muscles for action generates body heat.

When the body realizes that it needs to cool down to maintain a normal body temperature, people use behavioral or physiological responses. Behavioral methods include finding shade, changing clothes, grabbing an ice pack or a cool beverage, or finding indoor air conditioning. The body itself can use physiological mechanisms to help cool down. One way of cooling off is to sweat. When sweat evaporates off the skin, it helps to release the heat from the body. The body also helps bring heat from the core to the skin via the blood, so it can dissipate into the air (Périard, Racinais, & Sawka, 2015).

It’s important to note, too, that as you and your campers spend more time in the heat, your bodies adapt to the hot weather, and you become more resilient to it. This is called acclimatization.

Just be aware that heat illness doesn’t happen because the sun is out and it’s hot. Heat Illness happens when our body cannot tolerate the combination of environmental heat and the amount of work being performed. Education and preparation are the most powerful tools we have to protect kids in the heat.

When Do I Know Someone Has Heat Illness?

There are four different kinds of heat illness:

1. Heat syncope

• Definition: Dizziness that often occurs with people who are not used to being in the heat (unacclimatized), stand for a long time in the heat, and then change position. Often attributed to dehydration and low blood pressure, it usually occurs within the first five days of someone being exposed to the heat.
• Recognition: Brief episode of fainting associated with dizziness, tunnel vision, pale or sweaty skin, and a weak pulse.

2. Heat exhaustion

• Definition: The inability to continue exercise in the heat due to cardiovascular strain, dehydration, and energy depletion with an elevation of core temperature.
• Recognition: Someone suffering from heat exhaustion may have been exercising then suddenly feel very tired or fatigued. Heavy sweating is usually seen. The person might also collapse with minor cognitive changes.

3. Exertional heat injury

• Definition: Injury usually caused by strenuous exercise and environmental heat exposure.
• Recognition: Core temperature is usually elevated above 104°F but without the severe central nervous system (CNS) dysfunction seen in heat stroke.

4. Exertional heat stroke

• Definition: A person’s core temperature is substantially elevated above 104–105°F and they show signs of central nervous dysfunction.
• Recognition: Displays symptoms of irritability, confusion, altered consciousness, collapse, or even a seizure (Casa et al., 2015).

Heat illnesses should be taken very seriously. Heat illnesses such as exertional heat stroke can cause life-threatening damage and should be treated as quickly as possible! Rapid recognition and activation of a camp’s emergency action plan in this regard can save a life.

How Can We Prevent Heat Illness?

There are many steps you can take to help reduce the risk of heat illness. The first week of heat exposure is when the risk of heat illness is the highest. During this period, you and your campers should gradually increase the duration and intensity of activity in the heat. This allows your bodies time to adapt to the heat and become more tolerant through increased sweating and other mechanisms. Consistent access to hydration with cold water is essential to keeping everyone cool. Make rest breaks mandatory during activities, and take those breaks in a shaded or air-conditioned area whenever possible.

What Do I Do If I Think Someone Is Suffering from Heat Illness?

When someone is experiencing heat syncope or heat exhaustion, they should be moved to a shaded area or room with air conditioning while their vital signs are monitored and their legs are elevated above the level of their heart. Skin should also be cooled while they are actively hydrating.

The diagnosis and treatment of a heat-related illness, especially heat stroke, should be left to a camp medical professional, because it is a dangerous condition and requires specialized care. The best course of action you can take is to recognize the symptoms and initiate your camp’s emergency action plan (EAP). The EAP outlines and facilitates the immediate actions that must take place when someone recognizes an emergency. When arriving at your camp, make sure that you ask about reviewing and practicing the EAP and recognize the designated person in charge of the EAP.

Activating the EAP does not rely on medical professionals being present. When there is an emergency, the EAP should outline what kind of communication devices are available, where they are, and what number to call so you or someone you designate can give proper instructions on how to arrive at your location.

Information on developing an EAP can be found at koreystringer.institute.uconn.edu/eap (Korey Stringer Institute, 2025; Scarneo-Miller et al., 2024).

Condition	What It Is	Key Signs to Recognize	What You Should Do
Heat Syncope	Fainting episode often occurring in unacclimatized individuals standing in heat.	Dizziness, tunnel vision, pale or sweaty skin, brief fainting, weak pulse.	Move to shade/AC, elevate legs, monitor vitals, hydrate. Activate EAP if symptoms persist.
Heat Exhaustion	Body struggling to regulate temperature during heat exposure. Core temp elevated (usually <104–105°F).	Heavy sweating, fatigue, nausea, headache, dizziness, collapse with mild confusion.	Move to cool area, remove excess clothing, cool skin, hydrate, monitor. Activate EAP if symptoms worsen.
Exertional Heat Injury	Stress from prolonged elevated core temperature during exertion.	Very dark urine, muscle pain, elevated temperature, weakness.	Immediate medical evaluation required. Activate EAP.
Exertional Heat Stroke	Life-threatening condition. Core temperature >104–105°F with CNS dysfunction.	Confusion, irritability, collapse, seizure, altered consciousness.	Activate EAP immediately. Call EMS. This is a medical emergency. Diagnosis and treatment must be performed by trained medical professionals.

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References

Périard, J. D., Racinais, S. & M. N. Sawka, M. N. (2015, May 6). Adaptations and mechanisms of human heat acclimation: Applications for competitive athletes and sports. Scandinavian Journal of Medicine & Science in Sports 25, no. S1: 20–38. doi.org/10.1111/sms.12408

Casa, D. J., DeMartini, J. K., Bergeron, M. F., et al. (2015). National Athletic Trainers’ Association position statement: Exertional heat illnesses. Journal of Athletic Training 50(9): 986–1000. doi.org/10.4085/1062-6050-50.9.07

Korey Stringer Institute. (2025). Emergency Action Plans. University of Connecticut. koreystringer.institute.uconn.edu/eap

National Weather Service. (n.d.a). Severe weather definitions. weather.gov/bgm/severedefinitions

National Weather Service. (n.d.b). Tornado safety. weather.gov/mqt/tornadotips

Scarneo-Miller, S. E., Hosokawa, Y., Drezner, J. A., et al. (2024). National Athletic Trainers’ Association position statement: Emergency action plan development and implementation in sport. Journal of Athletic Training 59(6): 570–83. doi.org/10.4085/1062-6050-0521.23

Vaisala Xweather. (2025). The annual lightning report 2025. xweather.com/annual-lightning-report-2025#us-lightning-statistics

Ian Allen is lead meteorologist at Perry Weather, a weather safety platform that helps organizations prevent heat stress and severe weather risks by combining on-site monitoring, automated alerts, and expert guidance to support safer decisions for campers and staff. For more information, visit perryweather.com.

David Martin, PhD, is director of science at Perry Weather.