The Foreign Commonwealth Office is now officially warning against travel to Mexico.

They advise on their website that "If you live in a country affected by swine flu, you should monitor our travel advice and, as with other medical matters, assure yourself of your own healthcare arrangements. This might include obtaining access to anti-viral medicine. If you have any concerns over your own health, you should seek medical advice."

The FCO offers advice to people travelling to or already in affected areas. However, they recommend checking their travel advice regularly for updates on destinations.

Many people set to travel to areas affected by swine flu may not be covered by their travel insurance policy – even if they purchase it now, warns travelinsuranceguide.org.uk Most travel insurance policies won't cover any claims made in countries where the Foreign and Commonwealth Office has already warned against travel to the area, which means those planning to travel to Mexico won't be insured.

However, ABTA bonded package holidays should refund customers if their holiday is cancelled, regardless of travel insurance.

Even those who have booked their travel insurance may need to check that the policy they have includes cancellation cover – the key clause to examine. Many basic policies won't cover travellers for this, and many insurers give customers an option to opt out of cancellation cover when buying a policy to bring the price down.

Travellers with insurance who are concerned about the small print of their policy are advised to get in touch with their provider immediately.

Anyone still planning to travel to any destination who hasn't yet bought insurance is advised to talk to providers to find out if they would be covered specifically in the event of cancellation as a result of the swine flu outbreaks, rather than purchasing the cheapest cover without checking.

Louise Doherty of travelinsuranceguide.org.uk said: “Given the quick spread of swine flu from Mexico to other countries we would advise anyone travelling to any country to make certain they've got adequate cover to avoid getting caught out. Events like swine flu highlight the importance of getting insured with the right cover for your needs. ”