With the Siberian blast due to set upon the UK in the coming days, we thought it might be interesting to look at how different parts of the human body react to freezing temperatures; as well as some of the science behind these responses.

In addition, Treated.com’s own Dr Daniel Atkinson has some helpful suggestions on how to keep health problems at bay during inclement weather.

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What health problems can arise from colder weather?

As the ‘Siberian blast’ sweeps across the UK this week, temperatures are expected to be much lower than usual (and feel even lower); not just at night, but in the middle of the day too. Taking precautions to protect our health during inclement weather is therefore crucial.

We’re all familiar with how uncomfortable and unpleasant colder conditions can be; but it’s important to be mindful of the significant health risks severe cold weather poses too, and to take appropriate measures to protect ourselves from these.

Frostbite

Frostbite goes through several stages, the earliest of which is known as frostnip.

When someone exposed to the cold develops frostnip, the extremities (commonly the fingers, toes, ears or nose) become white; and sensation will be affected, characterised by feelings of numbness, tingling or ‘pins and needles’.

Frostbite is when this tissue begins to discolour into a dark red, and blisters develop. As it becomes more advanced (deep frostbite), these red patches will become blue and the blisters will start to scab over. At this point, the affected tissue may not be able to recover.

Frostbite requires medical attention; in minor cases, your GP may be able to provide guidance on how to treat it. If your symptoms are severe, however, you should call 999 or go to your nearest hospital.

During colder days, it’s important to take measures to prevent frostbite. Wrapping up warm and wearing clothes that cover your fingers, ears and nose (such as gloves, a hat or a hooded jacket and a scarf), as well as thick socks and waterproof boots, is essential.

Wet clothes can easily transfer the cold to susceptible parts of the body, so staying dry is also crucial. If you become wet, try to get indoors and change out of your wet clothes as soon as you can.

Exacerbation of asthma

Colder weather can make breathing harder for anyone; the airways aren’t as able to warm up and moisten the air before it reaches the lower respiratory tract. This can irritate the tissue inside the lungs and airways and cause muscles to spasm, which makes us cough.

As you might expect then, the cold weather can be particularly troublesome for people with asthma, and increase the likelihood of symptoms flaring up.

So, it’s vital to be prepared.

If you have asthma, make sure you have your reliever inhaler to hand, and adhere to the treatment plan set out by your doctor or asthma nurse. Stay warm, and cover up accordingly when you go outdoors, wearing a scarf to cover your throat, nose and mouth.

Asthma UK advises people with asthma to try breathing in through their nose more than through their mouth during colder conditions, as this enables the body to more effectively warm up the air before it reaches the lungs.

Allergic reactions

Cold urticaria is type of allergic skin reaction which develops when the body is exposed to lower temperatures. It is characterised by red, hive-like bumps on the skin, which can become irritated and itchy.

If you have allergies and think they might be triggered by cold weather, again, wrapping up and exposing yourself to the cold as little as possible can help. If you normally take antihistamines to help alleviate or prevent allergy symptoms, try to make sure you have access to these in case you need them.

It’s very rare, but possible, for someone to have a severe reaction to cold weather conditions (cold anaphylaxis). If you are affected by this, your allergy specialist will be able to give you detailed advice.

If you have a severe allergy and you are not sure whether cold weather may trigger it, avoid exposure to the cold as much you can by staying warm, and carry your auto-adrenaline injector pen (EpiPen) at all times as you normally would.

Injuries

Hospital accident and emergency departments will normally see a spike in admissions during colder periods, due to injuries sustained by slips and falls on icy surfaces.

It’s important for everyone to take precautions to avoid injury; but older people and those with osteoporosis are at increased risk of sustaining a broken bone, and will need to be extra careful.

When going outside, wear shoes or boots with a good grip, and try to walk on gritted lanes and paths wherever possible. Sticking to busier streets is likely to be less hazardous, as the ice and snow is quicker to melt from the presence of vehicles and footfall.

Try only to go outdoors during very cold and icy conditions if it’s essential; the less you walk around on slippery surfaces, the lower your chances of slipping.

The effects of freezing temperatures on different parts of the body

Brain: The hypothalamus gland in the brain responds to signals from nerve endings, and releases hormones in an effort to regulate body temperature and keep the vital organs warm. In doing this, it causes blood vessels to tighten (vasoconstriction).

Where the body is exposed to drastic cold weather for a prolonged period (hypothermia), the function of the hypothalamus can affect the thinking process; so someone may become less able to think clearly.

Heart: The body will need to consume more oxygen and pump more blood around the vital organs to keep warm, so the heart speeds up in order to meet this demand.

Fingers and toes: Loss of blood flow can particularly affect exposed fingers and toes, leading to discoloration (turning white, then blue), feelings of numbness (frostnip), and eventually pain and blistering (frostbite).

In advanced cases, tissue exposed to freezing temperatures for long periods (deep frostbite) can die (necrosis) and require surgical removal.

Hairs: The hormones released by the hypothalamus tell our skin to act as an insulator, to retain body heat. This causes hairs to cling to the body, and goosebumps to develop.

Nose: The skin inside the nose can become dry and cracked in cold weather, and susceptible to irritation.

Lungs: Usually, the upper respiratory tract (the nose, mouth and throat) warms and moistens air before it reaches the lungs. If the air is too cold for the body to do this, muscle tissue inside the respiratory tract can twitch and spasm, leading to difficulty breathing and coughing.

Unsurprisingly then, breathing in dry, cold air can be particularly exacerbating for asthmatics, and trigger symptoms.

Lips: The skin on the lips can become dry, thin and chapped, and more prone to cracking.

Muscles: Contractions in the muscles are initiated in an effort to generate energy and circulate blood, and this can lead to shivering. After long periods, they will become less coordinated and able to support the completion of basic movements.

Blood: Blood vessels become narrower so that they travel around more quickly, and oxygenate the body. The hormones released by the hypothalamus signal to these blood vessels to prioritise vital organs; and as such, less blood may travel to the extremities.

Skin: Cold weather can trigger urticaria, which is an allergic reaction causing red, rash-like  bumps to appear on the skin.

Urinary system: Increasing blood pressure (or vasoconstriction) causes more fluid to be filtered out from the blood by the kidneys (diuresis), and this can lead to an increased need to urinate.

Our doctor’s advice for staying well in cold weather:

  1. Wrap up warm. Make sure you only go outdoors wearing enough layers, and that you wear gloves and thick socks to help protect your fingers and toes from frostbite. It’s thought that we lose 7-10 percent of body heat through our head, so having appropriate headwear can help to maintain our body temperature.
  2. Try to limit your time outside. During freezing temperatures, try not to spend any more time outdoors than you absolutely need to. And if you have to go outside, see point 1 above.
  3. Move around. The more stationary you are, the more susceptible you will be to the cold. So try to stay active as much as possible, even if you’re indoors.
  4. Eat or drink something hot. During colder weather, hot meals and drinks can help your body to maintain a healthy core temperature.
  5. Be careful on ice. If you do go out, try to avoid walking on icy, slippery surfaces to reduce your chances of a fall; and use footwear with a good grip on the sole.