The Department for Environment, Food and Rural affairs have issued health warnings as Merseyside is forecast dangerously high pollution levels.
By Friday levels of air pollution are forecast to become high across Merseyside due to the warm air blowing in from France.
Officials have warned that adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors.
DEFRA said: “people with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion”.
They also warn that even normally healthy members of the public should reduce activity if they experience symptoms such as sore eyes, a cough or sore throat, especially during the hot weather.
Dr Samantha Walker, Director of Research and Policy at Asthma UK, says: “When air pollution is high it’s vital people with respiratory conditions including asthma check air pollution forecasts, carry their reliever inhaler with them at all times.
If anyone is concerned about how pollution may affect their asthma they can visit www.asthma.org.uk.
The Met Office have also reminded people that UV Levels at this time of year can be as strong as it is in September.
The Met Office have said: “the UK often experiences higher than normal UV levels in April and May as a result of ozone anomalies, where pockets of low ozone move across the UK.
“This means that there is a higher chance than normal of getting sunburnt in prolonged spells of sunshine”.
Wednesday was the hottest day of the year so far. Here was the beautiful scene looking over towards Liverpool: