Heat stress can be a problem particularly if travelling from a cold or temperate climate to a hot, tropical one. Acclimatisation generally takes up to 10 days, with excessive salt loss and reduced exercise tolerance experienced initially.

Incidence
Most common in travellers from the temperate southern winter who journey into the tropics, particularly those who are out of condition and/or overweight.

While physical fitness can make one better able to cope with the heat and accelerate acclimatisation, Travelvax advises all travellers to take sensible precautions.

Symptoms
Symptoms of heat exhaustion include: headache, dizziness, nausea, fatigue and thirst. Treatment is rest and rehydration.

Prevention
Hydration is the key:

• Drink at least 500mL of water after rising in the morning.
• Always carry water with you and maintain a constant intake (up to 1 litre per hour if exercising/walking).
• Minimise coffee and alcohol intake because of their diuretic effect.

Passing light yellow urine several times a day is the best indicator of adequate hydration. Thirst is experienced when a person is approximately one litre dehydrated.

Add salt to the diet. Salt replacement drinks used in sporting activities are not the best source of water as they can actually slow water absorption. Dilute these by at least 1:4.

Twenty minutes of light to moderate exercise in the cooler part of the day facilitates acclimatisation.

Wear light, cotton clothing.

Treatment

Heat Exhaustion
The key to treatment is rehydration and rest. To treat:

• Start with sips of cool-cold water.
• Gradually increase up to 250mls each 15 minutes.
• 2-3 litres may be required to rehydrate (in 2-3 hours).

Evacuation for further treatment is not required after successful rehydration.

Heat Stroke
If not treated early, the next stage of heat exhaustion is Heat Stroke - a medical emergency.
Changes in the level of consciousness, irritability, hallucinations and ataxia (unsteadiness in walking) are signs of Heat Stroke. Urgent evacuation to the nearest medical facility is required.

Hydration guide
An adult needs to drink about 3 litres of fluid a day in a hot climate; 5 litres or more if undertaking strenuous physical activity.

More information on heat stress is available during your pre-travel consultation with Travelvax. Call 1300 360 164 for the location of the clinic nearest to you.