Christmas in July is one of those wonderfully Australian inventions. We turn on the heating, cook a roast, pour the red wine and pretend — perhaps with a little artificial snow — that we're celebrating Christmas in the Northern Hemisphere.
But our Australian winter Christmas doesn't come close to the environmental extremes of a real Scandinavian one. My own ancestors lived in the far north of Sweden, where skin might move from –20°C outdoors to +20°C indoors within seconds. That's a 40-degree change — and while human skin is remarkably good at helping us regulate temperature, there's another, less visible change taking place. The river of water flowing through your skin suddenly changes speed.
And you don't need to live near the Arctic Circle to feel it. If you heat your home through a southern Australian winter, the air around you changes its relationship with water — and that can completely change how your skin feels.
Air is an invisible sponge
The important thing for your skin isn't simply whether the air is hot or cold. It's how much water the air holds relative to how much it could hold at that temperature. Warm air can carry far more water vapour than cold air. Imagine cold air holding a small sponge. Bring it indoors and heat it, and the sponge suddenly becomes much larger — but no extra water has been added. The newly enlarged sponge is now comparatively empty. In scientific terms, the relative humidity has fallen.
The air doesn't literally suck water from your face. But the difference between the moisture near your skin and the moisture in the surrounding air encourages water to evaporate more rapidly. That's why indoor heating can leave skin feeling tight, papery, rough or unexpectedly itchy — even though you're not standing out in the cold.
So Christmas in July is a good time to remember that skin doesn't experience "winter" according to the calendar. It experiences the microclimate we create around it.
Your skin is a living river, not a container
We talk about skin as though it were a wall that either holds water in or lets it out. It's far more interesting than that. Skin is alive — cells are continually forming, moving upward and being shed, and water keeps the outer layers flexible so the barrier functions properly.
A small amount of water is always diffusing from inside the body, through the skin, into the air. Scientists call this transepidermal water loss, or TEWL. The name makes it sound like something has gone wrong, but some movement is completely normal. The remarkable thing is that healthy skin holds an ocean of water within the body while letting only a carefully controlled trickle pass through its surface. In balanced conditions, the river moves gently enough to hydrate the upper layers while the barrier slows its escape. When the surrounding air turns very dry, the gradient steepens, and that gentle river starts behaving more like a rapid.
Supporting the gentle river this winter
Good winter skincare isn't about coating skin in ever-heavier layers. It's about helping living skin regulate its flow of water:
- avoid excessively hot, prolonged showers
- cleanse gently rather than repeatedly stripping surface lipids
- apply hydration to slightly damp skin
- support the barrier with appropriate lipids and emollients
- use water-associated molecules that help hold a hydrated environment at the surface
- where practical, add humidity to the room rather than simply turning the heater higher
This is exactly the thinking behind Phyaluronic® — our proprietary marine molecule. It isn't a generic seaweed extract; it's a distinct, molecule developed to help hold water at the skin's surface. Because at PhycoHealth, seaweeds ain't seaweeds.
So this Christmas in July, while we enjoy the vibe, spare a thought for the extraordinary river flowing invisibly through your skin. The problem isn't simply "cold weather" — it's the changing conversation between your skin and the air.
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This is part one of our Skin & Season series. Next: why the same winter room feels so different at 45 than it did at 25.