Food

Eating in restaurants is the biggest risk factor for contracting traveller's diarrhoea. Ways to avoid it include eating only freshly cooked food, and avoiding shellfish and food that has been sitting around in buffets. Peel all fruit, cook vegetables, and soak salads in iodine water for at least 20 minutes. Eat in busy res­taurants with a high turnover of customers.

Heat

Many parts of Southeast Asia are hot and humid throughout the year. For most people it takes most people at least two weeks to adapt to the climate. Swelling of the feet and ankles is common, as are muscle cramps caused by excessive sweating. Prevent these by avoid­ing dehydration and excessive activity in the heat. Take it easy when you first arrive. Don't eat salt tablets (they aggravate the gut) but do drink rehydration solution and eat salty food. Treat cramps by resting, rehydrating with double-strength rehydration solution and gently stretching.

Dehydration is the main contributor to heat exhaustion. Symptoms include feeling weak, headache, irritability, nausea or vom­iting, sweaty skin, a fast, weak pulse and a normal or slightly elevated body tempera­ture. Treatment involves getting out of the heat and/or sun, fanning the victim and ap­plying cool wet cloths to the skin, laying the victim flat with their legs raised and rehy­drating with water containing a quarter of a teaspoon of salt per litre. Recovery is usually rapid, though it is common to feel weak for some days afterwards.

Heatstroke is a serious medical emergency. Symptoms come on suddenly land include weakness, nausea, a hot dry body with a body temperature of over 41°C, dizziness, confusion, loss of coordination, seizures and eventually collapse and loss of consciousness. Seek medical help and commence cooling by getting the person out of the heat, removing their clothes, fanning them and applying cool wet cloths or ice to their body, especially to the groin and armpits.

Prickly heat is a common skin rash in the tropics, caused by sweat being trapped under the skin. The result is an itchy rash of tiny lumps. Treat by moving out of the heat and into an air-conditioned area for a few hours and by having cool showers. Creams and ointments clog the skin so they should be avoided. Locally bought prickly heat powder can be helpful.

Tropical fatigue is common in long-term expats based in the tropics. It's rarely due to disease and is caused by the climate, in­adequate mental rest, excessive alcohol intake and the demands of daily work in a different culture.

Insect Bites & Stings

Bedbugs don't carry disease but their bites are very itchy. They live in the cracks of furniture and walls and then migrate to the bed at night to feed on you. You can treat the itch with an antihistamine. Lice inhabit various parts of your body but most commonly your head and pubic area. Transmission is via close contact with an infected person, although body lice can come from contaminated bedclothes. They can be difficult to treat and you may need numerous applications of an anti-lice shampoo such as Permethrin, or in the case of body lice, with medicated creams or oint­ments. Pubic lice are usually contracted from sexual contact.

Ticks are contracted during walks in rural areas. They are commonly found be­hind the ears, on the belly and in armpits. If you have had a tick bite and experience symptoms such as a rash (at the site of the bite or elsewhere), fever or muscleaches you should see a doctor. Doxycycline prevents tick-borne diseases.

Leeches are found in humid forest areas. They do not transmit any disease but their kites are often intensely itchy for weeks afterwards and can easily become infected. Apply an iodine-based antiseptic to anyech bite to help prevent infection.

Bee and wasp stings mainly cause problems for people who are allergic to them. Anyone with a serious bee or wasp allergy should carry an injection of adrenaline (eg an Epipen) for emergency treatment. For others pain is the main problem - apply ice to the sting and take painkillers.

Parasites

Numerous parasites are common in local populations in Southeast Asia; however, most of these are rare in travellers. The two rules to follow if you wish to avoid parasitic infections are to wear shoes and to avoid eating raw food, especially fish, pork and vegetables. A number of parasites can be transmitted via the skin by walking barefoot including strongyloides, hookworm and cutaneous larva migrans.

Skin Problems

Fungal rashes are common in humid climates. There are two common fungal rashes that af­fect travellers. The first occurs in moist areas that get less air, such as the groin, armpits and between the toes. It starts as a red patch that slowly spreads and is usually itchy. Treatment involves keeping the skin dry, avoiding chafing and using an antifungal cream such   k as Clotrimazole or Lamisil. Tinea versicolor is also common - this fungus causes small, light-coloured patches, most commonly on the back, chest and shoulders. Consult a doc­tor for treatment.

Cuts and scratches become easily infected in humid climates. Take meticulous care of any cuts and scratches to prevent complica­tions such as abscesses. Immediately wash all wounds in clean water and apply antiseptic. If you develop signs of infection (increasing pain and redness) see a doctor. Divers and surfers should be particularly careful with coral cuts as they become easily infected.

Snakes

Southeast Asia is home to many species of both poisonous and harmless snakes. As­sume all snakes are poisonous and never try to catch one. Always wear boots and long pants if walking in an area that may have snakes. First-aid in the event of a snakebite involves pressure immobilisation via an elastic bandage firmly wrapped around the affected limb, starting at the bite site and working up towards the chest. The bandage should not be so tight that the ciroulation is cut off, and the fingers or toes should be kept free so the circulation can be checked. Immobilise the limb with a splint and carry the victim to medical attention. Do not use tourniquets or try to suck the venom out. Antivenom is available for most species.

Sunburn

Even on a cloudy day sunburn can occur rapidly. Always use a strong sunscreen (at least factor 30), making sure to reapply after a swim, and always wear a wide-brimmed hat and sunglasses outdoors. Avoid lying in the sun during the hottest part of the day (from 10am to 2pm). If you are sunburnt stay out of the sun until you have recovered, apply cool compresses and take painkill­ers for the discomfort. One percent hydro-cortisone cream applied twice daily is also helpful.