Gov. Ned Lamont\u2019s repeated refusals to reinstitute a statewide mask mandate has created a calamity for Connecticut. COVID cases are skyrocketing, and hospitals are overflowing, returning caseloads to nightmare levels not seen since the pandemic\u2019s darkest days. Front-line health care workers \u2014 nurses, respiratory therapists and doctors \u2014 are exhausted and stretched past capacity. The situation is a disaster, not just for COVID patients, but for everyone seeking care. Not surprisingly, death counts are rising again. A long overdue statewide mask mandate would mitigate this chaos. Data from the federal Centers for Disease Control and Prevention and elsewhere show that mandates decrease infections, hospitalizations and death. During the first COVID wave, Gov. Lamont issued a mandate, and Connecticut residents rose to the challenge, flattening the COVID curve, and helping hospitals escape the rationing and turmoil experienced in places such as Italy and New York City. Masks prevent disease by protecting wearers from inhaling SARS-CoV-2 into their lungs. They also decrease spread by preventing infected people from exhaling virus into the air. In the hierarchy of masks, surgical masks are better than cloth because they have an electrostatic charge that helps capture the virus. KF94, KN95 and medical grade N95 masks are even more effective because they fit snugly over the face, preventing air movement through the sides. My colleagues and I have spent countless hours wearing N95s at the bedside of COVID patients and therefore facing little risk of infection. The risk is far greater in community spaces such as indoor restaurants and bars, stores, supermarkets and gyms, where mask-wearing is inconsistent. When COVID rates declined in the spring of 2021, the CDC issued guidance that vaccinated people no longer needed to wear masks, and Connecticut relaxed restrictions. At the time, we hoped most state residents would pursue vaccination, but this didn\u2019t happen. Connecticut\u2019s vaccination rates are high compared to the rest of the country, but only 75 percent are fully vaccinated. Hundreds of thousands of people remain vulnerable to COVID because they\u2019re too young to be vaccinated, immunocompromised, or still refuse the shot despite its demonstrated safety and ability to prevent serious illness. Even among the fully vaccinated, many Connecticut residents have yet to receive booster shots, leaving them vulnerable to breakthrough infections, which can still spread disease. With the rise of the omicron variant and without a statewide mask mandate, it\u2019s no surprise that COVID rates are exploding. Connecticut\u2019s current guidance on mask-wearing is muddled and ineffective. The governor has repeatedly resisted calls to reinstitute a mask mandate despite the latest surge, leaving individual towns to create their own rules. This means if I go shopping in New Haven or Hamden, I must wear a mask, but not in North Haven or West Haven. The state permits individual businesses to require masks, but without the backup of a statewide mandate, business owners are forced to choose between confronting customers who refuse to wear masks and endangering the health of other customers and employees. Confusing messages from the Lamont administration, including repeated statements that the governor will not reinstitute a mandate, add to the frustration of medical and public health professionals working hard to promote mask use. Just as frustrating, Lamont has said he opposes a mandate because he considers it unenforceable. His spokesperson Max Reiss recently stated that the responsibility fell to individual cities and towns because \u201cit just wouldn\u2019t be possible to send out the state police to be the enforcers,\u201d as if Connecticut residents need the threat of police action to respond to common-sense public health rules. Connecticut residents are understandably tired of wearing masks, and some complain that mandates impinge on their personal liberties. My colleagues and I understand the fatigue and recognize the widespread frustration as the pandemic enters its third year with no sign of letting up. But if we wish to regain our freedoms \u2014 to dine out again and to see each other\u2019s faces again \u2014 the best thing we can do is come together to protect one another and bring this surge to a close. Connecticut faces a choice in the weeks ahead. Without a statewide mask mandate, hospitals may be pushed past their breaking point, subjecting state residents to needless suffering and death as unmasked individuals continue to contract and spread disease. But it doesn\u2019t have to be this way. Gov. Lamont could issue a mandate tomorrow. He could use his authority to bring the latest surge to a more rapid end. He could choose health over politics. He could save lives. It\u2019s not too late for him to take the steps we desperately need. Dr. Mark D. Siegel is a critical care pulmonologist at Yale-New Haven Hospital and a professor of medicine at Yale Medical School. The opinions expressed are his own and do not represent the official views of Yale Medical School or Yale-New Haven Hospital.