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Hot Tips for Managing Exertional Heat Illness from MUSC Health Sports Medicine

A person outside hot from the sun.

Heat can be both a friend and foe, especially during physical activity. Dakota Thompson, ATC, from MUSC Health Sports Medicine, sheds light on various exertional heat illnesses and how to recognize and manage them effectively.

Heat Illness Demystified: Understanding the Spectrum

The term 'heat illness' refers to when the body loses its ability to properly cool off thus leading to a heat imbalance within the body. There are varying degrees of severity that this can lead to, and it is important to understand different signs that can help prevent serious injury. Exertional heat illness can occur in mild environmental conditions due to multiple factors. These conditions can be induced either by an underlying medical condition, overexertion, poor hydration, or excessive heat exposure.

The different heat illnesses that are typically found with overexertion are as follows:

  • Exercise-associated muscle cramps
  • Heat syncope
  • Heat exhaustion
  • Heat stroke

There are important distinctions that will help you understand and respond appropriately to each condition.

Combatting Muscle Cramps: Tips for Prevention and Treatment

Exercise-associated muscle cramps are a very common condition that happens either during or after sporting events typically. This is not usually a severe condition associated with an elevated body temperature. This is a condition that can occur in warm or cool environments, and these muscle cramps are involuntary painful contractions that happen sporadically. They're typically caused by factors such as

  • Dehydration
  • Electrolyte imbalances
  • Impaired neuromuscular control
  • Fatigue

The best way to help prevent this condition from happening is with a collective approach that addresses these factors. The first step is to properly hydrate consistently throughout the day prior to activity, during, and after the event.

Secondly, to ensure that we have proper electrolytes we need a complete diet to get the essential vitamins and minerals. Salt can even be added to your drinking water to help get those needed electrolytes. A general estimation is to add about a half teaspoon of salt to a liter of water.

Lastly, an important step that can help is to make sure you are getting at least eight hours of sleep to reduce the buildup of fatigue. It is important to know that with all of these steps taken we cannot always prevent a muscle cramp from occurring as others tend to be "heavy sweaters" and might need more preparation than others. Treatment for this condition is rest and rehydration with a drink that has electrolytes and carbohydrates (sugar).

Beat the Heat: Strategies to Avoid Heat Syncope

Heat syncope (or 'orthostatic dizzines') is present in unfit individuals. What tends to happen is the person may be standing for a long time or quickly change their posture while out in the heat. These individuals can experience fainting in conjunction with dizziness, tunnel vision, pale skin, sweating and decreased pulse rate. This is caused by the blood pooling in the legs after a long period of standing.

The treatment for this condition should be to move the person to a shaded area, assess vital signs, elevate the legs above the level of the heart, cool off the person with ice bags or cool towels and rehydrate the person. To help prevent heat syncope, we must properly acclimate to the heat exposure over at least five days especially if sport equipment is going to be worn.

Recognizing Heat Exhaustion: Signs and Solutions

When individuals experience heat exhaustion there is usually an inability to perform well in the heat due to cardiovascular insufficiency, hypotension, central fatigue, and energy depletion. This condition is caused by an elevated body temperature of 101°F to 104°F. Common symptoms you may find with this condition include excessive fatigue, fainting, and collapse with minor cognitive disturbances (headache, dizziness, and confusion) while in physical activity.

These individuals could be experiencing hallucinations and other disorientating behaviors. They could be extremely weak, vomiting or nauseous, light-headed and have low blood pressure. Immediate action should be taken to help ensure there is no exacerbation of this condition.

You should remove any excess clothing or equipment from the person, and the person should be moved to a shaded or cool area and begin recovering the person via ice packs, cold towels and elevating the legs. This is an emergency that needs immediate intervention and warrants calling 9-1-1 for aid. Those who are qualified and equipped will typically take a rectal temperature reading to distinguish whether this is in fact heat exhaustion or heat stroke (more severe). These individuals should not return to activity on the same day as the episode takes place.

Heat Index Versus Wet Bulb Globe Temperature: Navigating Environmental Risks

This condition is associated with impaired cognitive abilities and a high core body temperature of 105°F or greater, which is caused by excessive heat production internally due to several different factors.

The environment plays a large role in these especially humid climates that limit our ability to cool ourselves off with our own sweat. We also tend to lose the ability to sweat with this condition due to depleting fluids over time.

Although hot weather is typically the reason for environmental, health, and safety management (EHS), it can also occur during intense physical activity in a moderate climate. Individuals showing signs of EHS will typically collapse or have symptoms of confusion, dizziness, loss of balance, irritability, aggressiveness and loss of consciousness. This is an emergency that needs immediate activation of emergency services and cooling of the individual. A cold tub is preferable for the treatment of EHS, and emergency personnel should be assessing rectal temperature during this process.

The individual should not be removed from the cold tub until the core body temperature has reached 102°F. If a rectal thermometer is not present to assess core body temperature, then you can go based on time in the cold tub. The rate of cooling is 1°F per three minutes of cold tub exposure, so roughly nine to 12 minutes of cold tub immersion can help reduce core temperature to a safe range.

The person needs to be transported to a hospital for further evaluation and treatment. Following the event, the individual needs at least a seven to 21 day rest period with normal blood work and physician clearance prior to returning to activity. It is advised to progress slowly with their physical activity following an EHS event.

Modifications for Heat index or Wet bulb Globe Temperature

A part of helping reduce the risk of a heat illness is to put in place modifications to activities and practices when the environmental conditions are unsafe. A helpful tool to have is a wet bulb globe temperature device which measures temperature, humidity, and wind speed to come up with a figure that determines an accurate representation of the conditions. If a wet bulb device is not present, you should refer to the reported heat index for the area you are in.

Below you'll find what temperature ranges will warrant specific types of activity modifications. It is important to know that this does not absolve you from injury, but only reduces the risk of injury. Everyone participating in activities should be taking a collective approach to their preparation to ensure they are ready to be physically active.

Heat Index

Wet Globe Temperature

Activity Guidelines

Less than 82°F

Less than 82°F

Normal activities permitted. Provide three separate water breaks each hour for at least three minutes during the workout.

Under 91°F

82°F to 86°F

Watch carefully for at-risk players. Provide three water breaks each hour for at least four minutes during the workout.

91°F to 103°F

87°F to 89°F

The maximum practice time is two hours. Football players are restricted to just a helmet, shoulder pads and shorts during practice. During conditioning, all protective equipment should be removed. For all sports, provide four water breaks each hour for at least four minutes each during the workout.

103°F to 125°F

90°F to 92.0°F

Maximum practice time is one hour. No equipment can be worn during this time. There may be no conditioning activities during this time as well. There must be 20 minutes of water breaks distributed during the one hour of practice.

Over 126°F

Less than 92.1°F

No outdoor workouts allowed during. It is acceptable to delay the practice until a cooler temperature has been reached.

Stay informed, stay safe. Visit MUSC Health Sports Medicine for more insights on heat illness prevention and management.