Drop in temperatures, frost and snow. The scenery resembles that of the northern hemisphere at Christmas, but no, it is the Brazilian winter in some states of the country.
But how much cold does it take to “freeze” someone? Well, the skin needs to be around 0ºC/-0.5ºC for this to occur. It can vary from hours to days and depends on the type of exposure, degree of cold, clothing and physical condition.
“Even at less than 15ºC it starts to be worrying”, warns Carolina Milanez, dermatologist at Hospital Heliópolis, in São Paulo. Even more so in constant wind and being on a motorcycle trip without protection: helmet, jacket, pants and warm gloves.
There may not even be frostbite, but hypothermia, which is another major concern — and is both a cause and a consequence of freezing to death. The human body needs to stay between 36ºC and 37.4ºC. Above that, it’s fever. But below it is also not good at all. At first, the condition triggers chills, tremors and, out of control, hallucinations and cardiac arrest.
When the cold is not so intense…
Some parts of the skin cool, but do not freeze. Among the most common symptoms, also resulting from dehydration, because in cold climates the air is essentially dry, are allergies, which can affect the face, ears and fingers. These places become red, itchy, sometimes burning and swelling, peeling and if left untreated they develop into lesions and chilblains.
“Children can have a condition called panniculitis (inflammation of areas of fat) and some diseases such as rosacea and psoriasis get worse”, also informs dermatologist Milanez.
Superficial frostbite is also common at this time and leaves the skin sensitive, thick and creased. Therefore, be careful with hot and long baths, as they contribute, in addition to the use of loofahs and antiseptic soaps, so that the lipid barrier of skin protection (natural fat) is removed, drying the skin and causing atopic dermatitis.
On the other hand, unexposed areas are better protected from the cold, but not from its indirect effects. This is the case with feet, which if they get damp/sweaty wrapped in socks and shoes for several days in a row, they can end up developing blisters, inflammation and mycoses. In this context, nails are also not spared. Fungal targets, can infect, deform and even fall off.
Thrombosis, dark lesion, necrosis
In extreme cold conditions, prone to freezing, the extremities of the body lose heat quickly. Hands and feet, especially, become stiff, numb, and cold, with a whitish or bluish appearance. Underneath the tissues, ice crystals are forming within or between the cells, which tends to result in foul-smelling, bloody blisters, thrombosis, and even necrosis.
“The female gender is more susceptible to the consequences of exposure to cold, the hands are smaller. But preexisting clinical conditions, such as diabetes, hypertension, coronary heart disease, hyperhidrosis, vasospastic disorders and Raynaud’s syndrome, of hypersensitivity to cold, are also factors of risk”, informs Bonno Van Bellen, angiologist and vascular surgeon at BP – A Beneficência Portuguesa de São Paulo.
The process of “frostbite”, if it reaches deeper layers, leads to gangrene (the region does not receive blood, darkens and dies from lack of oxygen, leading to amputation). However, defrosting with a direct source of dry heat (lamp, candle) or friction is not recommended. This is because the skin, numb and dehydrated, becomes extremely sensitive to burns and injuries. If there is a risk of refreezing, it also gets more complicated than already frozen.
How to avoid tissue damage?
Pointed out causes and effects, let’s go to the recommendations. To protect yourself from low temperatures and all that they represent, it is necessary to wear appropriate clothing (preferably lined), regular consumption of water, control of possible comorbidities, and specific treatments, both to prevent and prevent the aggravation of initially mild damage. .
Exposed (which is contraindicated) to freezing cold, it is necessary to seek shelter and warm up as you can: coats, blankets, hot drinks, exercises and thermal bags. In order not to lose heat, insulate the edges and, in the event of unforeseen circumstances, use newspaper and plastic bags to heat up.
“In more severe cases [com sinais de geladura], use warm water, between 37ºC and 39ºC. If there is no improvement, ask for help and urgent medical care”, says Ricardo Rodrigues, vascular surgeon and vascular surgery coordinator at Hospital São Marcos, in Recife.
Now, in the day to day of a cold but not unbearable climate, keep your skin healthy and avoid aggressions with sunscreen and products that improve its pH, with hydrating and invigorating actives (hyaluronic acid, collagen, antioxidants) — don’t forget of lips and ears.
Change wet clothes (which also favor hypothermia), put aside the consumption of cigarettes and alcohol and if there is itching, inflammation and scaling, seek a dermatologist.