1st Survival Summer Course - Basic Survival Medicine - Water

Here's a great topic for all the readers of this blog. This is a very helpful and interesting information that can
be used on a daily basis, so let's start:

Water, food and personal hygiene are primordial for surviving any environment. "During average daily exertion when the atmospheric temperature is 20 degrees celsius, the average adult loses and therefore requires 2 to 3 liters of water daily."

Typical consequences to one's health caused by dehydration are:

- a 5% loss of body fluids results in thirst, irritability, nausea and weakness.

- a 10% loss results in dizziness, headache, inability to walk and a tingling sensation in the limbs,

- a 15% loss results in dim vision, painful urination, swollen tongue, deafness, and a numb feeling in the skin,

- a loss greater than 15% of body fluids may result in death!!! 

The most common signs of dehydration are:

- dark urine with a very strong odour,

- low urine output,

- dark/sunken eyes,

- fatigue,

- emotional instability,

- loss of skin elasticity,

- delayed capillary refill,

- trench line down center of tongue,

- thirst (last on the list because you are already 2% dehydrated by the time you crave fluids).

Overall, it is very important to drink enough liquids to maintain a urine output of at least 0.5 liter every 24 hours. The advised water volume that one should intake in different scenarios is listed below:

low food intake day - 6 to 8 liters of water;

arid climate - 2.5 to 3.5 liters of water per hour/14 to 30 liters of water per day.

Electrolytes are important to maintain ones osmotic balance; adding a 0.25 teaspoon of table salt to 1 liter of water will result in a concentration of body salts that can be readily absorbed.

In case of extreme scarcity of water, rule of thumb states that a daily intake of half a liter of a 2 teaspoons of sugar per liter will help prevent dehydration for at least a week if water loss is put to a minimal rate.

Finally, a good way to estimate your water loss is to count the heart beats along with number of breaths per minute:

Pulse rate/minute               Breaths/minute               Water loss

100 beats                            12 to 20                          750 ml
100 to 120 beats                 20 to30                       0.75 to 1liter        
120 to 140 beats                 30 to 40                      1.5 to 2 liters      

That's all folks! Next week, foooooooood!

Image taken from Tips for preventing dehydration  on a San Diego Summer day, [http://www.mizutapt.com/tips-for-preventing-dehydration-on-a-san-diego-summer-day/], last visited on the 10th of September 2013, last updated on the 11th of July 2013.