08/01/2014 05:30 pm ET Updated Oct 01, 2014

Avoiding Deadly Dehydration: 8 Vital Questions to Ask Yourself Before You Hike

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Recently, we read the tragic news about an actor from the beloved Harry Potter series dying from heat-related illness. The 50-year-old British actor, David Legeno, played the werewolf villain Fenrir Greyback. Legeno died while hiking near Death Valley, California, according to the Inyo County Sheriff's Office.

The saddest part of this is that dehydration and heat-related illness are avoidable. Exercise increases body temperature. Our brains recognize the increased temperature and start the sweating process to cool our bodies. We can lose fluid at a very rapid rate, even faster than we can absorb water that we drink. We also lose valuable electrolytes, especially sodium. As we dehydrate, we are not able to cool our bodies as effectively, which elevates core body temperature. As core temperature elevates, our bodies try to cool it further. We lose more fluid and electrolytes. Even if we have water, we cannot replace it fast enough. The sodium loss can lead to muscle cramping. As we lose fluid, the blood is a little thicker and the heart has to work harder to pump the blood. Our mental focus and memory can be affected by dehydration.

So before you go on a hike, or what you consider a day hike, ask yourselves these questions:

  1. Are you physically prepared for the hike? If you did not make sure you are conditioned for a hike, perhaps you should have a level stroll through nature and enjoy the summer. If you hike and are not prepared, your system is inefficient, and you are likely to experience muscle fatigue and start overheating sooner as you climb in elevation.
  2. Do you have enough water with you in case you become lost on a hot summer hike? It is very easy to become lost in the hills, mountains or desert mountains. People who live in the city and want to have a hiking getaway while on vacation may not know how to navigate the terrain. The longer you hike, the more water you will need.
  3. Do you have any snacks with sodium? You will lose a great deal of sodium while you sweat. A good option is trail mix or something similar. Don't be shy about having sodium. You will need it.
  4. Do you have light clothing? The bottom layer should be lightweight and able to breathe easily. You may take a jacket and warm-up pants with you in case you spend the night on a mountainside. In some locations, the days are very warm and the night temperatures can plummet.
  5. Do you know where you are going? And, equally important, does anyone else know where you are going? If you're planning a long hike anywhere, review a map of your surroundings in advance and consider telling a friend or family member who could alert authorities should you fail to return on time.
  6. Do you know the weather forecast for the day and night? Fully understanding the anticipated temperature and humidity levels will help you plan accordingly.
  7. Do you have a charged mobile phone? If you become incapacitated due to dehydration, heat exhaustion, or if you suffer from an injury, you will need to call for help.
  8. Do you have a flashlight with new batteries? Should it take you longer than anticipated to return to your base camp or starting point, a flashlight could make a world of difference.

Unfortunately, the story of David Legeno is not unique. The hills and mountains near Palm Springs, California are the site of lost, dehydrated hikers on a near monthly basis. One site has a list of hikers who became lost, ran out of water, and some survived and some died during the 2009 - 2012 period. The common denominators are fatigue, dehydration, running out of water, becoming lost, not being physically prepared, and not having enough equipment.

The solution is to manage the dehydration by pre-hydrating. If you know you are going to have a significant demand on your body, you should start drinking more water hours before your event. If you will have demands for consecutive days (long hiking or camping trip), you need to replace the fluid you lost or you will become progressively more dehydrated each day.

The rule of thumb is to drink 20-24 ounces of fluid for every pound lost during exercise. You won't have a scale on a hiking or camping trip, but if you prepared for hiking in the months before your trip, you can get an idea of how much fluid you lose in a time frame during exercise. You should weigh yourself before and after training so you know how much weight you actually lost and how much fluid you need to replace.

If it is hot and you are sweating a great deal, you will need electrolytes too. A replacement drink can be used along with the water. Salty foods will help replace the lost sodium (assuming you are not struggling with high blood pressure). Wear appropriate light clothing on a hot day.

The American College of Sports Medicine has a good guideline that you can access easily.

Before you start on a hike that would challenge Lewis and Clark in the hot summer sun, take a few minutes to make sure you have everything that you need.