The public health institute RIVM on Wednesday took the unusual step of issuing a strong sun warning, urging people to cover up outdoors because of the risk of burning.

The international ultraviolet or UV index is set to hit seven on Wednesday and Thursday – which only happens around four times a year, the RIVM said.
This means just 15 minutes of exposure to the sun’s rays can lead to burning, increasing the risk of skin cancer.
A UV level of eight or above has been recorded just twice in the Netherlands in the past 15 years.