New York City's health commissioner issued a new public warning Tuesday advising older adults and people with preexisting conditions who are at an increased risk of severe COVID-related illnesses to limit nonessential activities outside the home effective immediately. Household members and caregivers of high-risk people are also advised to avoid going out except for essential purposes like medical care, grocery shopping and pharmacy necessities. Vulnerable people shouldn't have guests, either, city officials pleaded Tuesday as they said hospitalizations had doubled in just the last three weeks and are now at their highest levels since early June. "This escalation unfortunately follows a tragically familiar pattern," a somber NYC Commissioner of Health Dr. Dave Chokshi said. "Cases grow. Hospitalizations follow. And sadly, too many result in critical illness or even death." The urgent messaging comes as COVID spreads anew in New York to the point where Gov. Andrew Cuomo said "the valve no longer controls the spread." That statement effectively concedes that throttling indoor dining, gyms and other indoor activities statewide at this point has limited impact, with 65 percent of all new COVID cases in New York traced to small household gatherings.