Anyone with three key symptoms are being urged to wear face masks when going out to minimise the spread of winter illnesses. Flu and Covid-19 both become more prevalent during the colder months as people spend more time indoors, with close contact making it easier for the viruses to spread.

The latest data from the UK Health Security Agency (UKHSA) shows that flu cases are continuing to rise in the UK following an early start to the season and it is expected that cases will accelerate further over the coming weeks, with flu typically peaking in the winter months. The UKHSA is currently urging everyone over the age of 65, pregnant or with certain long-term health conditions to come forward for their flu jab to avoid getting seriously ill from the virus.

And as an extra precaution, health officials are also recommending that anyone who experiences three key flu or Covid-19 symptoms should wear a face mask when going out to help prevent spreading the virus to others. These symptoms include a high temperature, a cough, and feeling tired or achy.

Of course, flu and Covid can also cause a much wider array of symptoms, including a headache, sore throat, loss of appetite, nausea, diarrhoea and a blocked or runny nose, so it’s worth minimising contact with others and staying at home until your feel better if you experience any of these.

In the UKHSA’s latest winter surveillance bulletin, Dr Jamie Lopez Bernal, consultant epidemiologist at UKHSA, said: “Flu continues to increase among younger people despite the school half-term break. We expect the holidays gave flu a ‘firebreak’ and dampened the spread, but we do now expect to see further increases as people return to school and work.

“With this upward trend continuing, it’s more important than ever that those eligible for a free flu vaccine come forward. Vaccination remains the most effective way to protect yourself from serious illness and hospitalisation. Eligible groups can book their appointment through the NHS national booking system and parents should ensure school consent forms are completed or GP appointments are booked for younger children.

“Anyone with flu or COVID-19 symptoms – including high temperature, cough, and feeling tired or achy – should minimise contact with others, especially those who are vulnerable. If you need to go out with symptoms, consider wearing a face covering, wash hands regularly and ensure indoor spaces are well ventilated.”

According to the NHS, the following 10 health conditions mean that you are eligible to receive the flu vaccine for free this year and should book an appointment:

• conditions that affect your breathing, such as asthma (needing a steroid inhaler or tablets), chronic obstructive pulmonary disease (COPD) or cystic fibrosis
• heart conditions, such as coronary heart disease or heart failure
• chronic kidney disease
• liver disease, such as cirrhosis or hepatitis
• some conditions that affect your brain or nerves, such as Parkinson’s disease, motor neurone disease, multiple sclerosis or cerebral palsy
• diabetes or Addison’s disease
• a weakened immune system due to a condition such as HIV or AIDS, or due to a treatment such as chemotherapy or steroid medicine
• problems with your spleen, such as sickle cell disease, or if you’ve had your spleen removed
• a learning disability
• being very overweight – a body mass index (BMI) of 40 or above

If you have a health condition that is not included on this list and you’re not sure if you are eligible for the flu jab, the NHS advises speaking to your GP surgery to check.