With weather forecasters warning of low temperatures and possible severe frosts from Wednesday across the UK, the UK Health Security Agency is urging people to stay warm and watch out for others most at risk from the cold. But what are the dangers of cold weather?
How Does Cold Weather Directly Affect Health?
Public health officials are most concerned about the predictable and preventable consequences of cold weather. When temperatures plummet, hospitals see more patients with heart attacks, strokes and respiratory infections, including the flu. There is also a greater risk of hypothermia – when prolonged exposure to cold causes body temperature to drop below 35°C – and more falls and related injuries in icy conditions.
What other health problems occur in the cold?
In addition to the direct impact of cold weather on health, the cold also has indirect effects on well-being. Cold temperatures are associated with more psychological problems, such as depression. Other risks include carbon monoxide poisoning from poorly maintained or poorly ventilated boilers and cooking and heating appliances that burn fuel.
Who is most at risk?
There are many ways to be vulnerable to the cold. Children and the elderly are clearly at risk, albeit for different reasons. Children, especially those under the age of five, have a small body, so they lose heat quickly. Older people, especially those over 75, are more vulnerable and if they are socially isolated they may not have people to visit them to check whether their house is warm enough, for example.
The hardest hit are the most deprived. The homeless, or people sleeping on the street, are much more exposed to the cold than others and many will die on the streets this winter. People who don’t have enough fuel to heat their homes, or who live in homes with mold, are also on the higher risk list. This also applies to people with psychological problems, including dementia, which prevents people from taking care of themselves.
A large proportion of others are also vulnerable. Pregnant women should be careful, especially because of the potential impact of the cold on their foetus. Extreme cold, like extreme heat, has been linked to lower birth weight in babies. People with underlying health conditions, such as heart disease, stroke, asthma, chronic obstructive pulmonary disease (COPD), and diabetes can all experience worse symptoms. Cholesterol and blood pressure both rise in the colder months, increasing the risk of heart attack and stroke. With diabetes, blood sugar tends to creep up in cold weather, and when people’s hands get cold, blood testing can become more difficult.
At what temperature do the risks increase?
Official figures on extra deaths in winter suggest that the impact on health starts to increase when the average temperature drops below 12°C, but there are regional variations and factors such as how well insulated a person’s home is come into play. Research from UCL and the University of Bristol found that cold snaps, when temperatures drop for a few days, double the risk of heart attack and stroke.
What about the indoor temperature?
The UKHSA advises people with pre-existing medical conditions to heat their homes to a comfortable temperature, aiming for at least 18C in most used rooms, such as the living room and bedroom, and to keep bedroom windows closed at night.