British holidaymakers to America revelling in the strength of the pound against the dollar could suffer from the weakness of US suntan products, a new survey reveals.

As many as 84% of Britons do not realise that US sun protection factor ratings are only half the strength of UK ones, a survey found.

So a factor 20 suncream in America is only the same as a factor 10 in the UK.

It also re-enforced the findings of Malaria Awareness Week earlier this summer which showed that Britons were generally ignorant of the risk of malaria.

The survey by online pharmacy found 80% of Britons were unaware that many prime holiday destinations were malaria hotspots so took no precautions.

A quarter of the 527 people surveyed said they had experienced health problems while on holiday which required them to seek help from a doctor or pharmacist, with 34% saying it was a stressful and unpleasant experience and 19% declaring it ruined their holiday.

A total of 22% said they had difficulty finding or communicating with local doctors and pharmacists and 9% said they left the problem untreated until their return rather than get it treated locally.

Allcures superintendent pharmacist Mike Ritson said: "It's important that people do their research and seek proper advice from their pharmacist before they travel. "It's easy to get caught out when you're in an unfamiliar place, but there are simple and inexpensive precautions that people can take to minimise the risks before they travel, without spoiling their holiday. It's not a good idea to leave problems untreated as they may well become more serious."

The US Department of Homeland Security announced on June 15 a one-year extension of its Visa Waiver Programme (VWP) to October 26, 2006. VWP countries, including the UK, are required to have a biometric passport issuing system in place by October 26, 2006, in order to continue as members of the programme and benefit from visa free travel to the US after that date.

The US also announced a requirement that all new passports issued on or after October 26, 2005 must contain a digital photo image to enable the holder to travel to the USA visa free. This means that: British citizens with machine-readable passports containing a digital photo image will not require a visa to visit the USA because they meet the criteria of the October 26, 2005 VWP deadline. British citizens with machine-readable passports but without a digital photo will still be able to visit the USA visa free until the October 26, 2006 as their passport was issued before the October 26, 2005 deadline. Those without a machine-readable passport must have a machine-readable passport or apply for a US visa before visiting the USA.

The Foreign and Commonwealth Office and UK Passport Service (UKPS) welcomed the US decision, saying it would enable the UK to finalise the developments of our biometric programme and allows British visitors to continue to visit the US visa free.