Jules Eden, travel medicine specialist and founder of e-med, answers travellers' questions - as published in the following national publications

• The Guardian
• Independent On Sunday and/or
• Geographical Magazine

THE FLIGHT

For those allergic to aspirin when trying to prevent a DVT use clopidrogel. This works in the same way and should be used by any asthmatic, where aspirin could bring on an attack. This will need a prescription from your GP.

Any child old enough can have their ears equalized on descent by blowing gently into a balloon.

Anyone with medication needed on arrival to countries with a strict drug policy, such as diabetics should have a note translated into the local language to explain its uses.

AT SEA

Sea sickness is best avoided in the regular sufferer by actually seeing the waves so the boat's rocking can be anticipated.

Most over the counter sea sickness tablets are also sedatives so make sure you do not expect to be driving or diving and the other end.

A good alternative is ginger. In biscuits, tablets or tea it can help reduce any nausea.

If you are sick overboard check the wind direction first.

On smaller boats it is wise to take your own travel medical kit, as those on board can be quickly depleted, and you can be a long way from a pharmacy.



IN THE HEAT

There is more to fluid loss than straight forward sweating.

The wind in dry environments and upset stomachs can make you lose even more. Drink plenty.

If you do get diarrohea, then electrolyte replacement sachets are the best. However a flat sugary drink, such as cola, with a bit of salt in there can be a good quick alternative.

Water purified by tablets can taste awful. Use fresh lemon or lime juice to make it more palatable.

Anti-malarials need to be supplemented by mosquito avoidance to be 100% effective. Use nets, Vitamin B capsules and long trousers and shirts to be really sure.



IN THE COLD

The first sign of cold exposure is a dulling of the senses. Even if you are sweating keep warm and your head and chest covered.

Altitude sickness is worsened by smoking, alcohol and exercise.

So allow at least 2 to 3 days to acclimatise.

If you ascend to quickly and notice shortness of breath, slow it down, descend and even wait a day until you feel stronger.

ON YOUR RETURN

The incubation period of malaria is up to 2 weeks.

You must keep taking your tablets for the recommended period on your return. If you feel like you have a flu like illness tell your doctor about your travels and insist on a malaria blood film being done.

After a bad case of traveller's diarrohea it can be several weeks before all returns to normal.

Avoid excessive dairy products if you still feel unwell.

There are now many specialist medical centres that deal with the returning traveller and their medical problems.

They may be better than a quick NHS consultation.