What started as a grassroots movement in the United States over a decade ago, park prescriptions have become an evidence-based treatment regimen that helps people confront both mental and physical ailments by spending more time outdoors. In fact, at least nine countries now have nature prescription programs in some form. Park prescriptions fall under an area of medicine called "social prescribing," which encourages doctors to consider non-clinical treatments in primary mental and physical healthcare. "Social prescribing is a model of care delivery that enables health professionals to formally prescribe non-clinical community activities " including the arts, movement, nature, and service (volunteering) " to improve patient health, and at minimal patient cost," Social Prescribing USA's website reads. "Social prescribing is designed to address social determinants of health, including social connection. Built on a foundation of health equity and collaboration across sectors, social prescribing is intended to broaden health professional toolkits, rather than to replace pharmacological measures." Studies show that stress hormone levels drop after just 15 minutes outside; spending time in forests reduces inflammation and risks of lung infections; increasing nature time reduces risks of heart disease, high blood pressure, and diabetes; and seniors who live near walkable green spaces live longer.