The UV index is mentioned in every weather forecast, but many UK residents do not fully understand the health risks associated with sun exposure.
Four in 10 people said they do not check UV levels before going outside, with almost three quarters (74 per cent) believing there is no way to do this, a survey has found.
Nearly three-quarters of parents also do not protect their child’s eyes from harmful UV rays.
The skin also needs to be protected, using both sunscreen containing adequate sun protection factor (SPF) and clothing.
What are UV rays?
Sunlight is the main source of ultraviolet (UV) rays, which is why conditions are most dangerous on sunny days. The aim of the UV index is to warn people of increased risk, and encourage them change their behaviour in order to protect themselves against the risks of skin cancer, skin damage and other health problems.
The position of the sun in the sky, cloud cover and ozone amounts in the stratosphere all play a part in determining the UV index each day.
The UV index does not exceed eight in the UK, but in locations like the Mediterranean, nine and 10 are common.
UV index exposure
8-10: Very high
What have UV rays got to do with my eyes?
Damage caused by UV rays can be irreversible. Children’s eyes do not fully develop and provide natural lens protection until the age of 12, putting them in even more danger.
A survey carried out by the Met Office and Boots Opticians found that 31 per cent of people believe eyeballs cannot get sunburnt, with 78 per cent unconcerned about the sun’s effect on their eyes.
Only 30 per cent of parents said they worry about their children having too much exposure to UV and how it could lead to long term damage.
Wearing sunglasses that offer UV protection can help to keep your eyes safe, but only 43 per cent of people surveyed said they owned these.
A third of parents had no idea if their children’s sunglasses offer UV protection.
Sun worshippers basked in the hottest temperature of the year so far on Monday (23 July), with a scorching 33.3C recorded in England, and forecasters predict the mercury could soar above 34C by the end of the week.
People are being urged to stay inside, or at least avoid being in the sun between 11am and 3pm.
The 33.3C high was recorded at Santon Downham in Suffolk, but it is set to get even hotter, with temperatures expected to peak on Thursday and Friday.
The hottest July day on record is 36.7C (98F), which was reached at Heathrow on July 1 2015.
An amber ‘heat health watch’ warning has been issued for parts of England.