Minimizing Fluid Loss
Fluid loss is unavoidable but there are steps you can take to minimize the amount you lose.
The following steps may seem extreme but they will help you minimize fluid loss an ultimately increase your chances of survival:
Exerting yourself will cause you to sweat to stay cool, which uses up precious fluid.
Don’t smoke or drink alcohol
If you smoke or drink alcohol, your body will use fluid to flush out your kidneys etc as your body goes into a detoxification process.
Laying directly on hot ground or heated surfaces such as rocks
If feasible, dig or clear a shallow trench in a shady spot and lay in it. The earth underneath will be cooler than the hot surface; but you must consider that the shade will move with the sun.
If water is extremely scarce. If water is available but in smaller quantities eat only small amounts avoiding fat (digesting fat requires a lot of fluid to break it down). If you eat without keeping your fluids levels up, your body will take fluid from wherever it is available, for digestion. Unfortunately this will be from your vital organs and will cause further dehydration.
Fluid is lost through evaporation. Observing the steam which comes off your breath on a cold morning will give you some indication of the amount which can be lost through evaporation.
Things you can do
Breathe through the nose and keep your mouth closed as much as possible
This will help you to avoid loosing fluid through evaporation. Your mouth has a much larger, damp, surface area and therefore, you will lose much more fluid through your mouth than your nose.
Keep water in your mouth
When moving over a distance in the heat, take a sip of water and hold it in your mouth, without swallowing it, as you travel. This will slow the rate at which you lose fluid through breathing and it will help to stop your mouth and lips from drying out.
Travel at Night
In warmer regions, travel at night or early in the morning, where possible, and rest in a cool place during the heat of the day.
Stay in shade where possible. Where there is no shade readily available, then you should erect something which will provide shade.