Porch time: Bolsters immunity

At last, winter is over. But if you’re feeling under the weather, spending 30 minutes outdoors daily (either all at once or in smaller chunks) can cut symptom severity in half, plus trim four days off recovery time, British researchers say. Immunologist Jan Martel, M.D., explains that daily exposure to fresh air and sunlight—even March’s weaker UV rays—tamps down your body’s production of the immunity-suppressing stress hormone cortisol.