Each year, as warmth gives way to cold and communities draw indoors, the ancient rhythm of seasonal illness reasserts itself — and those who study its patterns are once again raising their voices in measured warning. Physicians across the country, having tracked viral behavior and population movement through the data of recent months, are forecasting a challenging sick season ahead, one that will press both healthcare systems and individual immune defenses. Their counsel is not alarm but anticipation: the time to prepare is now, before the wave arrives.