Illness, injury, accident and misfortune can strike at any time but such incidents can make you feel extremely vulnerable when away from home. Falling ill to the extent of needing urgent medical attention when on holiday can be a frightening experience - the reassurance and familiarity of calling the local GP is not an option, and the unfortunate individual can be left feeling lonely, isolated and afraid.

Despite the many cautionary real life stories of illness and injury that emerge each and every year - not even superstar footballers are immune from trouble, as England and Manchester United defender Chris Smalling discovered when he suffered food poisoning and fainted while on holiday in Bali - travel insurance remains an option that too many people simply choose not to take up. Of course, having insurance doesn’t prevent issues but it does provide peace of mind and support - not least financial - should you need help.

The Association of British Insurers has revealed that last year its members paid out £365 million - that’s £1 million every day - to ‘494,000 individuals and families who needed help’ when they were abroad. Over £196 million of the overall total was for emergency medical treatment. “Holidays are meant to be enjoyable and relaxing, but they can be traumatic for some travellers who become ill or are injured abroad,” commented Mark Shepherd of the ABI. “Medical treatment in foreign countries can cost tens of thousands, which is why it’s essential to have a travel insurance policy that will cover you should you need it.”

Yet too many don’t have travel insurance - and even those who take out a policy run the risk of invalidating their policy by failing to declare, according to research. One in 10 - some 12 per cent - of Brits with a pre-existing medical condition gamble with their policy by not declaring their condition. Analysis found that 45% of holidaymakers have a pre-existing condition but not all comply, leaving 1.8 million people at risk of invalidating their policies - and exposing themselves to potential bills of £3,500 if they need to make a claim while away.

“You should never head abroad without the right travel insurance policy in place and it’s important to make sure you’ve declared everything, including any medical conditions - even if your insurer hasn’t asked you specifically whether you have one,” said Kevin Pratt, consumer affairs expert at MoneySuperMarket, which conducted the research.

“The danger is that, if you don’t tell your insurer, your policy will be invalid and you won’t be covered if you have an accident or fall ill while abroad. For example, if you suffered a heart attack but hadn’t declared a pre-existing condition and the fact you’re on medication, you might have to pay your own medical bills and repatriation costs, which could potentially run into tens of thousands of pounds for those travelling to Europe, or hundreds of thousands for longer-haul trips.”

Declaring a pre-existing condition, then, is of the utmost importance when taking out a travel insurance policy, and having cover is absolutely, unequivocally vital - particularly if you’re travelling with young children or older family members, or planning a skiing or snowboarding trip. Decision to take out a policy soundly made, what remains next on your checklist is to select one which provides the right level of cover. It’s important you get that in place - if you’re going travelling around the world for six months it stands to reason that you’ll require different cover than if you’re off on a beach holiday for a week.

Policies obviously vary by insurer but the ABI recommends that any travel insurance policy has to include emergency medical treatment costs, which also means ambulance fees and hospital fees; repatriation cover - in other words, getting you home after treatment if you’ve been unable to stick to your original schedule; 24-hour assistance helplines for support and advice; and expenses to allow a spouse or close family relative to stay and travel with you if required.

Homework done, policy chosen and actioned, your preparation ahead of travelling is complete. The chances are that your holiday will pass off blissfully well, with no nasty and unpleasant surprises - but if disaster strikes and you need medical help, what should you do? What are the first steps you should take?

First of all, you must make sure you have all relevant documents with you - the travel insurance document itself, including the policy number, and an emergency contact telephone number. It’s a good idea to double check the number before travelling - you don’t want to mistake an office hours contact number for an emergency contact; you should have a 24-hour helpline so that you can reach someone at whatever time of day.

If you’re travelling within Europe, you should also have an EHIC - a European Health Insurance Card. This gives any holder the right to access state-provided healthcare while staying in another European Economic Area, which covers all the EU countries - still the UK, for now - plus Switzerland, Iceland, Norway and Liechtenstein. Essentially treatment should be made available in the same way it would to a permanent resident of that particular country.

If you need help, call your insurer on the provided number as soon as you can. In a difficult or distressing situation it can be hard to keep a cool head but make that telephone call. If you, or a family member or a close friend, needs medical treatment, ideally you will receive authorisation from the insurer first and they will agree to that treatment.

Provide details of the incident, and recount what has happened in as much detail as you can recall. It might be useful to make a few notes before initiating the conversation so that you have as much information as possible.

You may be faced with an emergency situation, and that could mean you don’t have the time to get treatment effectively signed off by the insurer first. If this is the case, you might have to pay up front for the treatment and then claim these costs back later from your insurer. Keep ALL receipts and medical certificates to make this process as smooth and straightforward as it can be. You’ll probably be expected to pay for smaller claims and claim that back.

If you haven’t suffered a medical emergency but still required treatment while on holiday and need to be reimbursed for any costs when you return home, go through your travel insurance paperwork carefully. Particular points to be aware of include the time limits for making a claim - there might be a deadline of a month, for example - and the excess on the policy. If that excess was set at £100 and you paid for medication totalling £75, then it’s probably not worth making a claim at all for obvious reasons.

All being well, your claim will be processed without a hitch and you won’t be out of pocket financially. But you might encounter a problem along the way and it’s helpful to be aware of potential hiccups. Common reasons for why your insurer might contest a claim include anything which falls under an exclusion clause in your policy, and it’s judged that you’ve been at fault or negligent at all - leaving bags unattended, not taking care of valuable items, reckless behaviour or taking part in a particular activity for which you didn’t secure designated cover.

If the claim process does not go well and you’re left unhappy at the outcome, you have the right to complain. The Financial Ombudsman Service can assist with questions in this regard.