We spend a lot on immunity. Supplements, vitamins, cold-pressed juices. But the most effective immune support available is free and happens automatically as long as you actually get enough sleep.
What your immune system does while you sleep
During deep sleep, your body produces cytokines, proteins that target infection and inflammation. Some are only made during sleep; they can't be stockpiled during the day. Your body also ramps up T-cell production overnight, the white blood cells responsible for identifying and destroying pathogens. Even one night of poor sleep can reduce T-cell activity significantly, leaving you measurably more vulnerable the following day.
How much sleep do you actually need?
Most adults need 7 to 9 hours for immune function to operate at its best. People sleeping fewer than 6 hours are significantly more likely to catch a cold when exposed to a virus. The less you sleep, the higher the risk and the relationship is consistent across the research.
Why winter makes it matter more
More time indoors means more exposure to circulating viruses. Shorter days disrupt melatonin and your sleep-wake cycle. And heavy or synthetic bedding can cause overheating, fragmenting sleep right when your body needs it most. Temperature-regulating bedding like wool helps your body maintain the stable sleep environment needed for deep, restorative rest.
Simple ways to sleep better this winter
- Keep your bedroom between 16°C and 19°C the sweet spot for deep sleep.
- Choose bedding that regulates temperature rather than just adds weight.
- Stick to consistent sleep and wake times your immune system runs on rhythm.
- Limit alcohol in the evening it reduces sleep quality and immune function.
- Cut screens an hour before bed to support natural melatonin production.
