This document provides guidelines for clinicians on the clinical management of patients with severe acute respiratory illness (SARI) when a novel coronavirus (nCoV) infection is suspected. It outlines recommendations for early recognition and triage of patients, immediate infection prevention and control measures, and early supportive care including oxygen therapy, conservative fluid management, empiric antimicrobials, and monitoring for clinical deterioration. The guidelines aim to optimize safe and effective management of critically ill patients and provide up-to-date interim guidance for healthcare workers.