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Tips to Prevent Heat Illness

Categories: Hiking Tips & Tutorials, Safety

Do you know how to prevent heat illness

Across the North Country Trail we are enjoying temperatures into the high 80’s and low 90’s. We are all ready to make the most of these last weeks of summer!

As you enjoy the Trail, keep in mind that with increased temperature and humidity comes the risk of heat illness. As you hike and enjoy the outdoors, follow these tips to prevent heat illness: Be aware of the hazards, know your personal risk factors, and take precautions.

The National Wildfire Coordinating Group has prepared the HIP (Heat Illness Prevention) Pocket Guide that you can carry with you on the Trail. You can download the HIP Pocket Guide here. Much of the information below is taken from the HIP Guide.

Know the H.E.A.T. Hazards:

Heat index
High humidity also increases the risk of heat illness because it interferes with the evaporation of sweat, your body’s way of cooling itself. 85 degrees and 70% humidity is more hazardous than 85 degrees and 30% humidity.

Exertion can be a hazard during high heat.
Exertion can be a hazard during high heat. Take frequent breaks.

Exertion level
Be especially careful if you are exerting yourself multiple days in a row. Your body many need extra recovery time. Also be aware of the toll strenuous elevation changes will take on your body in extreme heat. You may need to slow your pace!

Acclimatization and other individual risk factors.
Your body will not be acclimatized if your exposure is less than 4-5 days of any of the following: Increased heat exposure, increased exertion levels, or lack of quality sleep. So if you’re not used to the higher temperatures or strenuous exercise, and you plan to go hike 10 miles a day over a long weekend, while sleeping on the ground, you will be at higher risk for heat illness.

Time of exposure and duration of exposure.
If you will be exposed to the sun and humidity during the hottest parts of the day (10 am – 2 pm) or will be out for extended periods of time, your risk will be higher.

Pay attention to these Individual Risk Factors:

  • Sources of heat such as internal heat generated by physical labor.
  • Environmental conditions. High heat environments can restrict the body’s ability to evaporate sweat and cool itself. Direct sunshine can increase heat index values up to 15 degrees F.
  • Lower fitness levels requires more acclimatization time.
  • Overweight.
  • Minor illness.
  • Taking medications, whether prescribed or over the counter (ie: allergy or cold remedies, dietary aids, certain antibiotics, statins, ephedra and creatine)
  • Dehydration occurs during prolonged exertion when fluid loss is greater than fluid intake.
  • Excessive caffeine intake.
  • Prior history of heat illness.
  • Skin disorders such as heat rash and sunburn that prevent effective sweating.

Tactics for prevention:

  • Pay attention to the heat index through weather observations.
    Know your personal risk factors for heat illnesses.
    Know your personal risk factors for heat illnesses.
  • Adjust the exertion/rest cycle and take breaks as needed.
  • Reschedule activity for another day when heat index is lower.
  • Drink frequently (water and sports drinks), but do not exceed 1 1/2 quarts per hour or 12 quarts per day.
  • Snack throughout your hike.
  • Add table salt, or eat more salty foods when the heat category is very high (very hot/extremely hot).
  • Loosen clothing.
  • Wear clothing that is clean and allows dissipation of head and sweat from body
  • Take breaks and remove your backpack.

For more information:

– Our Tailgate Safety Series from the National Park Service includes an article on Heat Disorders, and an article on Hydration. Be sure to check out both articles to further educate yourself on staying safe in these high temperatures.

Heat Related Illnesses overview from WebMD

Warning signs and symptoms of heat related illnesses from the CDC

photo credits: top photo, Peter Zelinka