The U.K. experienced an early heatwave last week, but six out of 10 people confessed that they were unaware that the Sun Protection Factor (SPF) label alone is not enough to protect the skin from sun damage, according to The Guardian.

Sun creams are designed to protect the skin from UVA and UVB radiation, which may increase the risk of developing skin cancer. It is the SPF that indicates the level of protection offered against UVB, which causes sunburns. As for UVA protection, people have to look at a separate star rating of between zero and five.

UVAs actually penetrate the skin deeply, even during cloudy days. It is considered as the biggest cause of skin cancer.

"The most misunderstood factor when buying suncare [products] is that people think that SPF equals everything, but while choosing the right SPF is important it only protects against UVB rays and not the long-lasting damage resulting from UVA rays," said Simon Comins, Superdrug commercial director.

The health and beauty chain Superdrug conducted a study on 2,000 U.K. adults, which showed that 75 percent of Britons are not looking at both SPF and the top five-star protection when purchasing sun care.

From this number, 61 percent consider SPF as the most important factor in buying suncare products. They are also unaware that SPF does not protect the skin from UVA rays.

Meanwhile, nearly half or 44 percent do not know what SPF means, while one out of 10 even answered that they thought SPF equates to the number of minutes they are allowed to stay under the sun safely.

The British Skin Foundation actually reported that skin cancer is the most common form of cancer in the U.K., and the numbers are rising since at least 100,000 new cases are being diagnosed each year.

When purchasing sunscreen, skin experts suggest people select one with at least SPF30 and a four or five-star UVA rating. The sunscreen needs to be applied 20 to 30 minutes before going out, and should be re-applied every two hours.