Temperatures in Britain have taken a sharp dip this week and officials have warned the elderly and those with health conditions take extra care.
The weather has seen temperatures struggle to get above freezing as snow storms have swept in from the Russian Arctic.
But the cold conditions can trigger or worsen some health problems such as a sore throat, asthma and even a fever.
A fever can sometimes be confused with flu – but what is a fever and what are the symptoms?
A fever isn’t a separate illness. It’s when your temperature rises about its normal range, and this is often a symptom of flu.
As a general rule, a temperature of over 37.5C in children or adult is classed as a fever.
Depending on what’s causing your fever, you may experience additional signs and symptoms.
The Mayo Clinic says these can include:
- Chills and shivering
- Muscle aches
- Loss of appetite
- General weakness
How to treat a fever
Keeping yourself cool and taking paracetamol or ibuprofen is usually what’s needed to help reduce a fever, according to the NHS.
Cold weather could also put people at increased risk of asthma symptoms.
Asthma is a common lung condition that causes occasional breathing difficulties.
The long-term inflammatory disease also makes people’s airways very sensitive, so much so, cold or damp air can enter the airways and trigger them to go into spasm.
This can then cause asthma symptoms such as coughing, wheezing, shortness of breath and tightness in the chest.
There are other reasons why winter weather can also affect people with asthma.
Asthma UK says: “It’s near-impossible to avoid the cold and flu viruses that many people say make their asthma symptoms worse, although being vaccinated against flu each year can prevent you getting the most commons strain of flu virus.
“During cold, damp weather there are also more mould spores in the air, which can trigger asthma symptoms. And if you avoid going outside in the winter (as many people with asthma tell us they do), you may also be exposed to more indoor air pollutants like dust mite droppings and fumes from cooking or cleaning products.”
Freezing temperatures can also put you at risk of developing hypothermia.