HAWAII, Thailand and the Caribbean - exotic places in far-flung parts of the globe where you put the cares of the world to one side and relax in paradise.

But your trip of a lifetime could turn into a holiday from hell if you are not protected against deadly diseases.

Injections against diseases such as yellow fever can prove costly, after shelling out on flights and accommodation, but can save you heartache and expense in the long run.

For example, some countries, such as Brazil, will not let you in if you have travelled from an affected area and don't carry a vaccination certificate.

As well as unpleasant illnesses, overlooking vaccinations could land you with a painful medical bill.

In York, a travel clinic is run at the Boroughbridge Road Surgery, Lavender Grove, every Wednesday, Thursday and Saturday.

Helen Duffy, human resources manager of the Priory Medical Group, said people often did not have time to plan their vaccinations because of the option to book holidays a few days before travel.

"Because of the choice of booking holidays quickly and on the internet, we get a lot of people ringing up at the beginning of the week and saying they're going away a few days later to some far-flung places," she said. "But even if we could fit them in, which we would always try to do, then very often there is still an incubation period for vaccines.

"If you don't have certain vaccines in advance then there's no point in having them. Some of them take a month, some take 14 days before they're into your system.

"Because folk are going to so many diverse places, it is important to start early when you're planning. Your inoculations and malaria tablets are important because you have to take a course over a period of time.

"If you're planning something like a round-the-world trip, then try and plan six months in advance. Time is really of the essence."

Prices differ depending on the injection and course of tablets, but Helen said they were worth the expense.

"It's not negotiable really," she said.

"We give our patients advice for free and the charge for medicine is just to cover the pharmaceutical costs.

"The advice we give you will also depend on your accommodation; if you're going backpacking you're going to need more protection than if you were staying in a five-star hotel.

"If you're going trekking in Nepal in the hills then you're going to be exposed to more dangers than if you were in a modern city.

"It doesn't just depend on how far you're going and how exotic it is, but also on the terrain.

"There can be repercussions if you don't inoculate yourself and some symptoms don't appear at the time, they appear afterwards, which would ruin both your holiday and the memory of it."

The Travel Clinic is open on Wednesdays between 1.30pm and 4.30pm, Thursdays between 5.50pm and 7.50pm, and Saturdays between 9am and 11.20am.

It is not a drop-in clinic. Phone the surgery on 01904 784484 first for an appointment and advice.

:: Health travel checklist

Make sure you have got all the documents you need, such as your passport and vaccination certificates

Check your insurance policy so you know what your insurance will pay for

Give the doctor the generic name of any medication you are taking

Contact your travel representative if you have one

Tell the doctor if you have been to any other countries on the trip

Contact British Consular officials if you need to get back to the UK quickly

If you pay for any treatment or drugs and plan to claim on your insurance or get a refund, keep all receipts, special proofs of purchase, price tags and labels.

:: Diseases you can be inoculated against

POLIO

A viral disease usually transmitted through contaminated food and water. An effective vaccine is available and boosters are usually given every ten years for those travelling into at risk areas.

HEPATITIS A

Usually transmitted through contaminated food and water, attacks the liver and may lead to jaundice and a prolonged illness. Vaccines are highly effective and, if boosted at 6 to 12 months, provide long-term protection.

TYPHOID FEVER

Can cause a high fever which may progress to coma. An injected vaccine is available which is boosted every three years. Vaccination is generally less important for short stay travellers staying in good accommodation.

TETANUS

A serious bacterial disease usually contracted after contamination of wounds (especially deep puncture wounds). The inactivated vaccine is boosted every ten years.

DIPHTHERIA

Usually transmitted by close contact with infected people. The low dose diphtheria vaccine is used to boost adults and adolescents. The UK Department of Health recommend the use of combined tetanus/diphtheria/polio vaccine when diphtheria boosters are indicated.

HEPATITIS B

The hepatitis B virus is transmitted sexually and by puncture of the skin with contaminated instruments. The disease can lead to liver damage and eventual liver failure. Vaccine usually given as a three dose course over six months.

RABIES

Transmitted by saliva of infected animals and can be contracted by a scratch or a lick. Rabies is invariably fatal once symptoms begin.

Pre-exposure vaccines are recommended for long-stay travellers, those going away from medical help (24 hours plus) and animal handlers. All travellers should seek post-exposure vaccines if bitten/scratched.

MALARIA

A dangerous disease spread by mosquitoes that bite from dusk to dawn.

Symptoms include fever and in some cases complications affecting the kidneys, liver, brain and blood. Seek medical attention immediately.

YELLOW FEVER

An arthropod borne virus considered to be one of the most lethal viral diseases. The endemic zones for the disease are in tropical regions of Africa and South America.

Updated: 11:19 Friday, January 20, 2006