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

Q. We are taking our 3-month-old daughter on a two and a half hour flight before the New Year. Could you please advise us on what steps we should take to make the flight as comfortable and safe for her as possible.

A. Fortunately for you the flight is fairly short so there should not be too long for her to get annoyed with the environment and close proximity of other passengers.

The key point really is in take off and landing. Cabin pressure will alter and she will need to equalize. We adults of course can wiggle our jaws, or blow into a closed nose. She will just feel an odd pressure, which may get painful for her. So make sure she is on her bottle. The gentle sucking will move the jaw enough do the best to open up the Eustachian tube so the middle ear gets equalized.

Get an aisle seat. If she does erupt and need to be rocked then its best done walking down the aisle.

Keep a change of nappy and lots of wipes handy and it will be cramped in the plane loo. So do not go in with a massive bag, just the bare essentials.

Finally for your own comfort, take a spare top. You may well be the target for an airsick projectile vomit, and you don’t want to sit for the flight covered in milky posset.

Q. I am planning to take a six year old and a one year old to Costa Rica at the end of December and January. What precautions should we take?

A. Of all the Central American countries, Costa Rica is probably one of the safest to take kids to. It has a good health system and an enviable standard of living if compared to others around it.

The base shots to have are Hepatitis A and typhoid. Antimalarials are needed too, and over the counter chloroquine and paludrine are recommended, but this can change, so for the absolute latest needs you could go onto www.e-med.co.uk and access the information via the Travel Clinic pages.

However, depending on where you are going there may be no need for malaria precautions.

Costa Rica has some of the worlds best high montane rainforest, home of the Resplendant Quetzal, a bird you will see in images everywhere, and up this high, the mosquito finds it a tad cold and so there’s no need for daily tablets.

The only other tip from my experience is that beaches on the West coast seem to support the thorniest of bushes, branches of which lie like some medieval trap under the sand. So get them rubber soled surf booties if they plan a run around.

Q. Much as I look forward to the annual family holiday, it's always blighted by the fact that my two boys suffer from travel sickness. Needless to say this makes any journey an ordeal for all of us. We're driving up to Scotland to see relatives this summer - can you suggest anything that might help us get there in one piece?

A. Yes, I agree, the ordeal of a long drive up to Scotland with the thought that your 2 children will be complaining of nausea the whole way is enough to make you rethink the plan.

There are now quite a few remedies available for this problem. They fall into the categories of over the counter medication and homeopathic type treatments so things have moved on now since the days of a barley sugar sweets and I-spy. Having said that, playing car games has it's place in preventing the problem.

The reason kids can get car or travel sick is that when a car corners, the balance centre in the inner ear sends signals to the brain about which direction movement is in.

Now if there are no visual stimuli to help with this then the brain gets a bit confused and creates a sense of nausea.

Classically if you are reading in the car on a winding road, then this feeling can come very quickly. So it's always best to make sure the children are looking out of the windows and seeing the direction you are about to go.

This doesn't work for every child and I advise that you try some of the homeopathic remedies first. Nelsons have a product called "Travella" which a lot of people have recommended to me, it's available over the counter at most Health Shops.

Also useful are those acupressure bands, which are elastic wrist bands with a plastic bead that presses onto a point on the wrist. Again these work well, are side effect free and quite cheap.

If you get nowhere with these two, then there are tablets called cinnarizine that act to stabilise the balance centres. These should be taken 2 hours before you set off, and then every 8 hours of your journey.

They are effective for not just car sickness but also airplane and seasickness too. The child dose is half the adult, but children under 5 should not take them unless you have spoken to your doctor first.

They have one main side effect, which is mild sedation and drowsiness, useful if you are a passenger at times, but not so good if you're the driver!

So don't take them if you need to stay alert.

There are stronger medications available, but I think these should only be taken after guidance from your doctor as there are greater risks of side effects that outweigh the real problems that travel sickness can cause.

So realistically, if you can keep your kids amused, their eyes on the road and take the straightest route possible you should be fine.

Q. My daughter, who has ME, is thinking about travelling to New York. Her condition makes it difficult and painful to sit in an aircraft seat for any length of time. Is there an alternative way for her to travel? We have thought about sea travel on, say, a cargo ship. Is this still possible? Alternatively, is it possible to book a number of seats on an aircraft? We would be very grateful for any suggestions.

A. As you well know with ME, or myalgic encephalitis, to give it its full name, there are times when the "myalgic" part can be worse than others.

Myalgia means muscle aching and pains which characterise this affliction, and as you rightly say, the thought of being seated in a cramped airline seat with little legroom and the inability to get up and walk around a lot is quite a worrying one.

Your idea of a cargo ship is a good one, and there are plenty of vessels that do this crossing frequently. However the crossing can be a long one, up to 5 or 6 days sometimes, with stops at other destinations for cargo to be on and off loaded which can extend the journey. I would probably recommend she tries a cruise liner instead though if she wants to go by sea, as it is more comfortable, quicker and most importantly, each vessel would have its own Ships Doctor.

Ships doctors are not mandatory on cargo vessels, and they would have a more basic First Aid qualified seaman on board. I assume that with her problem your daughter is not as steady on her feet as she was once, and this would be a problem if she fell on the deck in rough seas, as she is likely to hurt herself, and so it is important to have the best medical attendant as is possible. Of course cruise liners may be more expensive than cargo vessels, but I think the cost difference is worth it in her case.

I suppose the bottom line is finances and also how quickly she needs to get there, certainly plane travel may be more uncomfortable but 8 hours of relative discomfort could well outweigh the 5 to 6 days on a boat. If she flies and needs to stretch out then First or Business class is a good option but again expensive for anyone.

There is something I have given for people in similar situations in the past, and that is a low dose muscle relaxant than can be taken an hour or so into the flight as things begin to get uncomfortable. A 5 milligram dose of diazepam often helps as it is a muscle relaxant, and just one tablet on each flight is not enough to cause any problems of addiction, which is a possible side effect of this drug if it is taken frequently and for a long time. Her doctor should be understanding enough to give it to her if she asks. One last thing, if she doesn't want to book several seats is to ask the airline what time is the least popular and underbooked period and hope that she can find 3 or 4 empty seats together to stretch out on.

Q. We are flying to Thailand for Christmas with 3 children aged 2, 4 and 7. The last time we did this the trip became a nightmare, mainly for the other passengers as all 3 cried the whole way. Is there anything we can do to keep them asleep this time.

A. There are several elixirs available that do have sedating properties as one of their effects. However most doctors would not advocate their use, in that knocking out your kids for a 16 hour flight will only lead to other problems at the other end of the flight.

When you are asleep in your Thai hotel, they will be up and running for the next day and you will regret not marrying up your respective sleep cycles.

Also there is no sleeping tablet or syrup that is liscenced for children of that age.

What I recommend on the flight is that if you can bring enough entertainments for in flight amusements and distraction, that may quell their boredom enough until they sleep normally.

But I do understand your position and I have in the past given patients various syrups when they know their children will play up and they don't mind the consequences at the other end.

The main group of medication are called "antihistamines", and they are normally used for itchy, allergic disorders in kids. One of their main side effects is that of mild sedation, in fact enough to put a child to sleep for 4 to 5 hours. The 3 that are commonly used are called Phenergan, Vallergan and Piriton. Now reports of the first 2 are that they work well, but in a few children they go the other way and become hyperactive in flight. So I always suggest using a test dose a few days before they fly to make sure this reaction doesn't happen. Infact I prefer to use the Piriton syrup for children for this reason, as it has no real downside. Ask your doctor for a scrip and they will tell you of the appropriate dosages.

The other thing that can diturb children during a flight is that when the plane descends and the cabin pressure increases, the fact that they cannot equalise their ears as easily as an adult can cause problems. A good trick is to take a balloon with you and get them to try to blow it up on descent as this will help them to blow air into the middle ear.

Finally, if you are taking 3 kids to Asia, I also recommend a medical pack designed with children in mind. There are a few on the market, but they differ in quality and contents and most are not differentiated for baby, toddler or young child. If anyone contacts e-med we can recommend the most appropriate one for the ages involved and the destination.

The last thing you want to be doing in a strange city, is to be trying to find Calpol at 3 a.m. as your child has a fever.

Q. I have heard about the sad death of the young girl after the long haul flight from Australia, what exactly caused this and how can I prevent it happening to me when I fly there next month?

A. What happened to this girl was sadly preventable and also becoming more frequent as flights get longer and seats get more cramped.

She suffered a blood clot in the deep venous system of her calf. This is called a deep venous thrombosis or DVT. If part of this clot dislodges, it travels up the venous system back to the heart, through the right side of the heart and to the lungs. This is what happens to cause death , as if a big enough piece of the clot gets to the lungs then it causes the blockage of the blood supply there. This is called a pulmonary embolus and it can be fatal.

Recent research has shown that up to 1 in 4 people that get a DVT have all been in a long haul flight in the last few weeks. You can see that this is an incredible statistic as a lot of the smaller DVTs go undiagnosed as they don't cause the classic symptoms of swelling of the calf with redness and pain in the same area.

The reason that air travel can cause this problem is due to several factors, all which seem to coexist on these flights.
Firstly for a clot to form the blood needs to be very slow moving. This occurs inflight as passengers sit in a cramped position with their knees bent. This can restrict the flow back of the blood and help a clot form. The next problem is with dehydration. It is said that you should drink a litre of fluid every 3 hours on a flight, but what is normally given out, ie alcohol can actually dehydrate you more as it makes you need to urinate more often. As you now have less circulating fluid volume the chances of clot formation are a lot higher.

Finally the swelling in your lower legs due to the position you sit in also causes to constrict the veins too. So these factors can cause a clot, but also being on the contraceptive pill, obesity and smoking too will all increase the risk.

What is recommended to stay alright inflight is to keep your toes moving by regularly going for a walk up and down the aisle, and also keeping well hydrated.

I would also suggest that anyone who is high risk, and by that I mean overweight, OCP taking smokers who have a family history of clots forming, take a dose of 75mg of aspirin before they fly, as this thins the blood enough to stop the DVT forming. However if you suffer from stomach ulceration or allergy to aspirin then there is a shot of a blood thinning agent called heparin available.

If anyone experiences tender calf swelling or chest pain and shortness of breath after a flight, then please seek medical attention immediately.

Q. I am hoping to go on holiday to the Caribbean at Christmas with my baby, who will be one then. We are thinking of going to one of the islands nearest to the equator. Will it be too hot for him? What jabs will he need and are there any special precautions we should take?

A. It is difficult to judge exactly how hot it's going to be in the Caribbean at that time of year. Obviously it will be hotter than the UK, the temperature will probably be up in the 80F [late 20sC] at times, but remember this is just an average and it could get even hotter at that time of the year there.

You must make sure that your hotel has air conditioning and that they can guarantee its reliability, so if it is too hot then you are prepared. The same goes for any car you may rent out there too.

You will need to take plenty of high factor sun block, at least factor 40 and a broad brimmed hat for your child. Light cotton clothing that covers the arms and legs will also prevent too much sun exposure. Your child will need to drink more fluids than when in the UK so don't let your child get dehydrated by waiting too long between drinks, and always keep their water mug handy.

Depending on which island you go to a Hepatitis A shot may be needed. It is best to check this with your GP at least 2 weeks before you go. At 1 year old your baby should have been immunised for tetanus and polio by now so don't worry about that.

As for other precautions and tips when travelling with a young child in this area, make sure you only used bottled water to make up feeds as there is a risk of infection if you use tap water, especially if it is rainy season.

You will probably be spending a lot of time near the beach, and if your child is paddling there is a chance that sea urchins dwell near the rocks close to the shore. I usually recommend baby reef shoes to protect against this and some of the other dangers like hot sand and jellyfish in the shallows.

There is no danger of malaria in that part of the Caribbean, but there are enough biting insects around to warrant awareness especially on the beach where sand flies can be a problem. These can spread an infection known as cutaneous leishmaniasis which presents as a non-healing skin rash.

Whilst on the beach still, if your child gets an eruption under the skin that looks like a worm then your doctor should check that it could be cutaneous larva migrans, which is a parasite that normally infects dogs but can be caught by humans too whist lying on the sand.

To protect against these sort of infections wear protective clothing and wash down in fresh water after being on the beach.
Finally, if you go inland there are a few poisonous snakes on some of the islands, but they are rarely seen as they shy away from human contact, so make some noise as you go through the jungle.

Q. My little boy who is 5 has been diagnosed with Atopic Asthma. We are wanting to go to Canada later in the year. Is it safe to fly when you have asthma.

A. It is fine to fly with atopic or allergic asthma. This is brought on by
certain allergens like animal hair, pollens or the dreaded house dust mite. These do not really exist in the aeroplane.

Likewise when you get to Canada, he should be fine because there are
completely different allergens there which he has not been sensitised to.

But if you want to veer on to the safe side, always take his blue Ventolin inhaler with you both. If he does start to get wheezy, as predicted by a Peak Flow Meter then he should take a couple of puffs on this to stop the bronchoconstriction.

Rarely in flight if this does not do the trick, the only thing to do is use
the oxygen available, and then max the dose of the inhaler up to 20 or so puffs.

However this is only in extreme circumstances, and you would be very unlucky to have to do this.

A. My GP has told me that my child should not fly with his ear infection.

As we are due to go to Mexico in a weeks time should we cancel now or risk that it will be fine by then.

Q. This is a hard call to make without looking into the actual ear.

If he has an outer ear infection, i.e of the outer ear canal, then he is actually OK to fly.

The issue is with equalizing. This involves the middle ear and the Eustachian tube. If he has a middle ear infection then it can affect the patency of these organs, and not allow air to pass in or out of the middle ear. The poor laddie will scream the whole flight as the air expands on ascent but can't get out.

A treated middle ear infection could be better in 5 or 6 days.

I suggest you make an appointment with your doctor to have it assessed the day before the flight. If when he looks at the eardrum, it moves on swallowing and blowing into a closed nose then Eustachian function is now fine and you can all fly away together.

Q. My partner and I plan to return home to Australia next year, stopping over in South Korea for a week on the way. By then, our child will be 7 months old. Will the baby have had sufficient vaccinations by then? Or would it be more sensible to fly straight home without stopping?

A. I think that it's best to go for the direct flight.

There should be no problems, however the vaccines that your child could have are not liscensed for the under 1 year olds.

The main shots that an adult would have are Hepatitis A and Typhoid, along with perhaps, Japanese Encephalitis.

The spec from the vaccine makers is that they will not guarantee safety and efficacy [i.e will it work] for the under one year olds.

So if your stop over is just a whim to check out the airline's flexibility,
then just get back to Oz, if it's something very important, then weigh it all up with the advice of your local GP.

Q. We're taking our children, aged six and eight, to a coastal hotel in The Gambia for a fortnight over Christmas. What do we need to know to protect them? We're concerned about everything from Yellow fever to crocodiles and venomous creatures.

A. They are going to need a fair few shots I am afraid, and as the doc approaches with the needles they'll wish they were going to Disneyland.

For starters they will need anti-malarial medication.

Good news though as a junior version of malarone has just been launched. This is the best tablet for malaria, but before they had to break an adult tablet and hope they got the right amount. Now it's a special kids dose. Take it for 2 days before travel and only a week after you get back.

As for the shots, they must be up to date on tetanus, diptheria, polio and typhoid.

They also need Hepatitis A and Yellow Fever.

So that's quite a collection of pre-travel meds to take.

If you are going at Christmas then you need to start the courses quite soon.

So either contact your GP or a specialist travel clinic to ask what is the best combination to take them in as it may be too much to have them all in one go.

It is unlikely to be bitten by poisonous beasties. But do try and avoid situations. Look where you are walking for snakes. And don't dangle your hands in the water on river boat trips. Its croc bait.