Asthma sufferers are being warned of a risk of 'deadly' attacks as pollen levels and temperatures soar.

The mercury is set to hit 29C in East Lancashire today, with pollen levels 'high', according to the Met Office.

Dr Andy Whittamore, clinical lead at Asthma UK and a practising GP, said: "A toxic cocktail of hot humid weather and rising pollen levels this week could be extremely hazardous for the 5.4 million people in the UK with asthma, triggering deadly asthma attacks.

"Hot air and hay fever can cause people's airways to narrow, leaving them struggling to breathe, with symptoms like coughing, wheezing, a tight chest and breathlessness.

"Hot weather can also increase the amount of pollutants, pollen and mould in the air which can trigger asthma symptoms."

She urged people to keep their medication close at hand, adding: "If you are worried about the weather or hay fever affecting your asthma, make sure you take your hay fever medicines, keep taking your regular preventer as prescribed by your doctor and carry your blue reliever inhaler at all times.

"We'd advise you to drink lots of water to prevent dehydration and plan any outdoor activities for earlier in the day when the air quality tends to be better."

Temperatures will increase as the week progresses, with highs of 31C predicted for Thursday.

Ruth May, chief nursing officer for England, said: "Like lots of people I'm looking forward to having fun in the sun with family and friends, but nobody wants to spend a pleasant day stuck in a hospital or urgent treatment centre.

"It's really important to take simple precautions like drinking plenty of water, using high-factor sunscreen and remembering to take allergy medication if you need it - as is making sure to check in on neighbours and loved ones who can suffer the most from heat and pollen."

People with minor illnesses are urged to check the NHS website or call 111 for help.