Mark McShane, Food Hygiene Certificate expert, reveals 7 foods that 'can lead to serious illness' while travelling

This might be the one that first springs to mind since it's quite a common routine that many people adapt to when they travel abroad. 

It's a simple fact that water systems vary from place to place, and the water we consume at home is what our bodies are most used to.

Mark says: "Ice in drinks can often be made from unfiltered or tap water that contains bacteria or parasites." 

Even if there aren't bacteria in the water, chances are your body won't be accustomed to local water, so best to stick to bottled.

The same thought process applies to raw salads, since they're often washed in untreated tap water, which can cause bugs.

Nobody likes an undercooked egg. But more importantly, it can be a way of catching bacteria. Mark explains that it's not always obvious. 

"Undercooked eggs can be found in sauces, desserts and some street food, and can carry salmonella if not treated properly."

Shellfish is another one that people might immediately think of when it comes to risky foods, regardless of location. 

Anyone who has had a dodgy oyster will know it does not make for a pleasant experience. 

Mark says: "Buffet seafoods easily spoil if not kept cold, and shellfish are high risk in warm climates."

This one took us by surprise; desserts normally seem a pretty safe option. 

However, certain ingredients could spell trouble in certain environments.

"Fresh cream and custard in hot climates can quickly turn dangerous," advises Mark.

Dairy in itself can often be fine, but it depends on the process. "Avoid cheeses and milk that don't clearly state they're pasteurised," says Mark. 

Pasteurisation is the process of using heat to kill off the unhealthy and harmful bacteria in milk; it also extends the shelf life of a product.

Raw meat seems obvious, but some people are very partial to rare or blue steak. 

But approach with caution, Mark says, "especially minced meats and kebabs cooked on low heat."

He adds: "Trust your instincts – if it doesn't look right or smell right, don't risk it. 

"Food poisoning can ruin your trip, and in some cases, lead to hospital treatment or long-term illness."