Smoke fumes from fireworks and burning wood from bonfires can linger in the air, according to the charity. It creates air pollution in the immediate area, and could instigate asthma attacks.
Two-thirds of asthma patients said bad air quality made their symptoms worse – the equivalent to about 3.5 million people in the UK.
Coupled with cold weather, the charity warned bonfire night could create a “deadly” combination for asthma patients.
The charity’s warning came after the public were warned to expect a rather chilly Guy Fawkes’ night this year.
“Lots of people love the excitement of bonfire night, but for some people with asthma it could be deadly,” said Asthma UK’s resident GP, Dr Andy Whittamore.
“We don’t want people with asthma to miss out, but we want them to be safe and aware of the increased risk this bonfire night, when pollution will be higher than normal.
“We are urging people with asthma, or parents of children with asthma, to make sure they have their reliever inhaler with them, and want people’s friends and family to know what to do if their asthma symptoms suddenly get worse.”
Asthma UK recommended patients stand well back and admire fireworks from afar, if the smoke is making them cough.
People with asthma should also wrap a scarf over their nose and mouth, the charity added, as it will warm up the air before breathing it in.
Always carry your blue reliever inhaler, and continue to take your brown preventative inhaler as prescribed.
The charity’s warning came after paramedics were called by asthma patient Jessika’s, 25, husband a couple of years ago on fireworks night.
Jessika said: “A few years ago, I had a terrifying asthma attack on bonfire night. I was at a family gathering and my gasps of amazement at the fireworks display soon turned into gasps for breath.
“The smoke from the fireworks made me wheeze so badly that my husband had to call an ambulance. I didn’t have my reliever inhaler with me.
“Now, I always carry my reliever inhaler with me on bonfire night and I want to urge people with asthma like me do the same – it could save your life.”
About 5.4 million people are currently being treated for asthma.
Two-thirds of asthma deaths are preventable, according to Asthma UK.