When engaging in outdoor activities at high altitudes, it is easy to experience chest tightness and dehydration. This is because sweating (sweat contains 0.25% NaCl), respiration, urination, and diarrhea can all lead to fluid loss from the body. In cold mountainous regions, the extremely dry air causes sweat on the skin surface to evaporate quickly, while rapid mouth breathing expels large amounts of moisture—often unnoticed—resulting in symptoms of dehydration (hypertonic dehydration). For illnesses caused by extreme heat or cold, as well as acute mountain sickness, maintaining adequate fluid intake is an important preventive and treatment measure. It not only reduces the likelihood of illness but also significantly enhances the overall physiological function of mountaineers.
Hypertonic Dehydration (Body Dehydration)
Symptoms:
(1) Mild dehydration: Thirst. Fluid loss is 2–4% of body weight.
(2) Moderate dehydration: Extreme thirst, fatigue, reduced urination, dark and cloudy urine, dry lips and tongue, irritability, poor skin elasticity, and sunken eye sockets. Fluid loss is 4–6% of body weight.
(3) Severe dehydration: In addition to the above symptoms, hallucinations, delirium, and even coma may occur. Fluid loss is approximately more than 6% of body weight.
Preventive Measures for Body Dehydration:
(1) Drink plenty of water. Drinking hot tea during camp activities can both prevent dehydration and provide warmth. Before setting out on a trek, drink a glass of water, and consume an appropriate amount of fluids (equivalent beverages) every 30 minutes during the journey. Daily fluid intake should be >2000 ml/day (during camp activities) to 3000 ml/day (while trekking).
(2) During strenuous exercise, do not replace water with high-concentration fruit juices or other highly concentrated fluids (such as chocolate drinks, cereal drinks, etc.). Recommended beverages: hot water, tea, low-concentration fruit juice drinks, vitamin C effervescent tablet drinks, or other sports drinks.
(3) Also eat salted nuts or trail food appropriately to replenish lost body salts.
(4) Carry a 1L–2L insulated bottle during the trek.
(5) Distribute water intake evenly during the trek, taking full account of the need for water on the return journey and preparation for emergencies.
(6) Avoid eating snow or ice to prevent freezing injuries to the mouth and throat. (7) Quit smoking, avoid alcohol, and reduce intake of spicy and high-salt foods.
Treatment for Body Dehydration:
(1) Drink water. First consider drinking low-concentration glucose water or other sugar-containing hot beverages. Intravenous fluid administration may be necessary if needed.
(2) Appropriately supplement salts (oral rehydration salts) and vitamins.
(3) Consume hot liquid foods (fruit drinks, chocolate beverages) or semi-liquid foods (porridge, cereal, or soft noodles) to replenish the body’s energy. If the patient’s thirst is alleviated, mood gradually stabilizes, and urination begins, it indicates improvement. Clear consciousness, coherent responses, and clear urine color suggest that dehydration has been corrected.