Asthmatics have been warned to take extra precautions this weekend amid fears rising pollen levels could trigger life-threatening attacks.
The Met Office is forecasting high pollen levels in most of England and Wales from Friday, with medium levels elsewhere in the UK.
Asthma and Lung UK said more than three million people in the UK have lung conditions such as asthma or chronic obstructive pulmonary disease (COPD) and are at risk of flare-ups or seizures, which kill around four Britons every day.
Pollen can trigger symptoms such as chest tightness, difficulty breathing and shortness of breath in more than half of people with asthma (59 percent) and more than a quarter of people with chronic obstructive pulmonary disease (COPD), according to research by the charity.
Allergies can cause the airways to narrow and build up sticky mucus, making it difficult to breathe.
Those deemed at risk have been instructed to continue taking their prophylactic inhalers if they use them and to carry their reliever inhaler with them at all times.
Asthma and Lung UK has also recommended that prone asthma sufferers use a steroid nasal spray or stay indoors on days with high pollen counts. For England and Wales, the values are expected to remain high from Friday to Monday.
“Tree pollen currently includes oak, small amounts of birch and some grass pollen,” the Met Office said in its forecast, adding that spores are “limited”.
dr Asthma and Lung UK clinical director Andy Whittamore said: “When pollen concentrations are at their highest, it can be deadly for people with lung conditions such as asthma, who can experience severe symptoms and life-threatening attacks.
“These attacks can leave people gasping for breath, which can be frightening, but there are things they can do to take care of themselves.
“Using your prophylactic inhalers as directed is important as the medicine reduces airway sensitivity and swelling, helping to prevent symptoms such as wheezing and coughing before they even occur.
“We also advise people to have their reliever inhalers with them each day, especially when out and about enjoying the sun, in case pollen is causing a flare-up of their symptoms.
Reliver inhalers quickly relax muscles in the airways, providing immediate relief of symptoms during an attack.
dr Whittamore added: “Thirdly, people can use a steroid nasal spray daily along with non-drowsy antihistamine pills to stop the allergic reaction.
“People should also check pollen and air pollution forecasts in their area so they can avoid going outside on days when pollen levels are high.”
Climate change is believed to be responsible for the lengthening of the annual allergy season and higher pollen counts. Scientists believe these trends will worsen as the planet continues to warm.
A study published last month in the journal Nature Communications says the pollen season could start 10 to 40 days earlier than usual and last five to 20 days longer, with pollen concentrations tripling in some places if carbon emissions aren’t curbed will.
Warmer weather allows plants to bloom earlier and bloom further later in the season, while carbon dioxide in the air from burning fuels like coal, gasoline and natural gas helps plants produce more pollen, the scientists said.
Another study published last year says the allergy season has become longer and richer in pollen since the 1990s, reflecting rising global temperatures.