Why does the cold make us blush?

It is common to experience redness in winter, particularly on the extremities of the body, such as the fingers, ears, and nose, which are delicate areas. This redness is a result of the drop in temperatures felt during the winter months, as well as the accompanying cold and dry wind. This environment is conducive to the disruption of the skin barrier. Studies have indeed shown that the change of season is accompanied by a decrease of about 40% in the levels of ceramides, cholesterol and other lipids in the stratum corneum. This layer can no longer fulfil its protective function properly, resulting in an increase in skin dehydration and water loss.

The fragility of the skin during winter makes it more susceptible to environmental irritants and allergens, which induces a mild skin inflammation. This is characterised by an increase in the levels of interleukin 1-α (IL-α), pro-inflammatory cytokines, as well as cortisol and the number of dermal mast cells. The release of these chemical mediators of inflammation manifests at the macroscopic level as the appearance of skin redness.

These rednesses can also be explained by a change in blood circulation within the body. Indeed, when the ambient temperature decreases, the blood vessels located near the skin's surface contract. This vasoconstriction is a physiological response aimed at reducing body heat loss by decreasing blood flow to the skin. This allows to maintain the body's temperature stable at around 36.6°C (homeothermy) and to prevent hypothermia.

Indeed, during winter, the body is frequently subjected to abrupt changes in temperature due to the significant contrasts between the potentially heavily heated interiors of homes and the outdoors. These environmental changes trigger phenomena of successive vasoconstriction-vasodilation. The latter is characterised by an increase in the diameter of the capillaries and an intensification of blood flow, which visually manifests as the appearance of redness on the face.

In order to prevent and alleviate redness caused by the harshness of winter, it is necessary to revise one's skincare routine to best protect the skin.

• Re-evaluating one's shower routine.

  To gently cleanse the skin, the use of a makeup remover in the form of a balm or oil rich in lipids and a cleansing milk with a creamy texture is preferable for skin that has been assaulted by the cold. To counteract redness, opt for skincare products containing hydrating agents (glycerine, aloe vera...) and soothing agents (bisabolol, calendula macerate...). Also consider limiting your shower time and lowering the water temperature to a warm but comfortable degree.

• Maintaining hydrated skin under all circumstances.

  In both summer and winter, hydration is key to protecting the skin. This is particularly the case when temperatures are low and the skin is prone to redness. To strengthen the skin barrier and the hydrolipidic film, opt for re-lipidising agents such as vegetable oils (apricot oil, camelina oil, safflower oil...) renowned for their nourishing, protective and regenerative properties. If you feel the need, it may be relevant to change your moisturising cream and choose a richer texture.

• Do not underestimate the impact of the sun.

  Just because we see less of the sun in winter, it doesn't mean it's any less harmful. Indeed, contrary to popular belief, UV rays can penetrate through clouds and windows and reach the skin. This is particularly true during snowy periods or if you are skiing. The higher you ascend in altitude, the more you expose yourself to risks, as the rays reflected by the snow are potent. To protect the skin from irritations and redness caused by the sun, it is therefore recommended to apply a sunscreen, even in winter.

• Why not a concealer?

  If your winter redness becomes a concern, you can certainly use a green concealer to camouflage it. The effectiveness of this product relies on the ability of the colour green to cancel out red. Indeed, these colours are complementary, which means they neutralise each other when combined. Applying a few drops of green concealer in the morning, followed or not by a tinted serum will allow you to prevent and conceal redness caused by the cold.

• GALL Y. & al. Seasonal variability in the biophysical properties of stratum corneum from different anatomical sites. Skin Research and Technology (2000).

• ROGIERS V. & al. Seasonal impacts on the condition of nasolabial skin. Skin Pharmacology and Physiology (2009).

• PIOT B. & al. Influence of season on certain skin characteristics: winter vs. summer, as observed in 354 Shanghai women of varying ages. International Journal of Cosmetic Science (2011).