Trekking is often confused with mountaineering. While mountaineering is a carefully pre-planned adventure, trekking requires little preparation. Mountaineering is more technical in nature and hazardous as well, but this is not the case with trekking. Trekking has its own delights as well as thrils.

On a trek, the following tips will prove useful

• Well fitting strong boots with a couple of pairs of woollen socks. The boots should have been used before the trek, otherwise the wearer could wind up with blisters

• A first aid set in case of minor accidents and illnesses

• A raincoat, to cope up with the uncertainties of weather

• Chocolates, lozenges, candy, glucose and dry fruit all of which provide extra energy

• It is advisable not to exhaust that energy by walking fast. A trekker sapped of energy will not find the trek enjoyable

• High altitude sickness or mountain sickness is a phenomenon normally observed above 10000ft. The earliest sympton is a continuous headache. Though emergency medicines do exist but the best solution is to come down.

• The trekker should try the treks above 10,000 ft after due acclimatization.

• Overstrain also results in mountain sickness. Trekker should avoid overstraining especially above 10,000 ft

• The packing of backpack is also an art. A poorly packed rucksack may result in uncomfortable trekking and the body getting tired early. One approach is to keep the heavier items on the top. This results in minimum of bending moments on the body and hence a comfortable walk. Loosly packed rucksack also results in discomfiture in walking.

• A good trekker takes longer steps. The short rests should be followed by well distributed longer rests.

• In Himalayas, the afternoon rains are a common phenomenon, hence a trekker should start as early as possible so as to reach the destination before 1-2 pm.

• Physical conditioning is a must before undertaking any kind of trek.

"Precaution saves life". Though adventure sports do involve a bit of risk and hazards but knowledge makes a difference between life and death. Acclimatisation is important for trekking above 10,000 ft(3000 m). Rarefied air at High Altitude may lead to what is called High Altitude Sickness. An early observation of a symptom results in saving of a life. Hence knowing the various symptoms and stages of High Altitude Sickness or Mountain Sickness may help. The following listing comes from Indian Army's long experience in service and combat at these heights.

• Acute Mountain Sickness (AMS) is a throbbing frontal headache that is aggravated by exertion and particularly in the mornings is the commonest ailment. Other symptons include malaise, lassitude, disinclination to work, loss of appetite, nausea vomiting, shortness of breath on exertion and disturbed sleep. If untreated this may progress to -

• High Altitude Pulmonary Oedema (HAPO). Caused primarily by rapid ascent, cold, re-entry and exertion, it is potentially life threatening. Beginning with a headache, there is body ache, cough, breathlessness on exertion which is progressive, non-anginal chest pain, anorexia, disturbed sleep, vomiting and giddiness. At times a fever may be the presenting symptom. In severe cases there may be associated symptoms of -

• High Altitude Cereberal Oedema (HACO), the most dreaded but also the least common of high altitude illnesses. The onset is with AMS, and the alteration of consciousness is the most important feature of HACO. Complaints of dimness of vision, dizziness, vomitting and which may progress to stupor and coma.

• Pulmonary Arterial Hypertension of High Altitude: The onset is usually with effort intolerance, anginal chest pain, haenoptysis and swelling of the feet and face along with diminution in the urine output.

• Chronic Mountain Sickness is largely restricted to young or middle-aged men and particularly amongst smokers. And the early and dominant symptoms are referable to the central nervous system with headache, somnolence, loss of memory, dizziness, paraesthesias and neuropsychiatric symptoms. Others symptoms include effort intolerance, bleeding manifestations and later also mild cardiac failure.

High altitude illnesses unrelated to acclimatisation

• High Altitude Retinopathy: About a third to almost half of those exposed to extreme high altitudes are likely to be affected by retinal haemorrhages. While the exact cause is not known, there is an increase in retinal blood flow with vasodilatation. In addition, sudden surges in blood pressure on exertion may aggravate or precipitate retinal haemorrhage. It can be resolved spontaneously.

• Snow Blindness is less common than is believed and is caused by the exposure to ultraviolet radiation is relatively higher at these altitudes, as well as the increased reflection of such radiation from the snow surface.

• Hypothermia is diagnosed when the core body temperature falls below 35º C, and below 25º C it is lethal. Up to 33º C the onset is subtle and there is a decrease in shivering. As the core temperature falls further the individual becomes careless about his clothing leading to a vicious circle. The individual becomes uncooperative, memory is affected, there is somnolence leading to stupor, coma and finally death.

• Local Cold Injury includes -
  • Chillblains: the non-freezing injury to the skin occurs at temperatures just above freezing. The affected part is red and causes intense irritation.
  • Trench Foot: This occurs after prolonged contact with moist cold such as water or mud at temperatures above freezing.
  • Frost Bite: The most serious of these injuries usually occurs at temperatures below freezing, and is caused by the freezing of extracellular fluid with the formation of ice crystals. This is aggravated by freezing of water in the cells and inhibition of enzyme systems. The onset is usually insidious with pain and numbness followed by loss of sensation. The severity of Frost Bite depends upon the duration of exposure and the temperature, and at its most serious can lead to the loss of limbs.