Carbon monoxide (CO) poisoning typically occurs in enclosed spaces and often affects    groups of people, making it relatively easy to suspect based on the circumstances. However,  CO poisoning can also occur in situations where it is not easily anticipated. We encountered  a case of CO poisoning that occurred in a non-enclosed space and was initially suspected   to be heat stroke. A 60-year-old ferryman exposed to exhaust fumes from a diesel-powered  motorboat in a non-enclosed workspace who presented with a generalized seizure,  metabolic acidosis, tachycardia, and hypotension. Carboxyhemoglobin (COHb) level was  38.2%, confirming significant CO exposure. Prompt intervention with oxygen therapy and  norepinephrine stabilized the patient, with improvement noted over 72 hours and COHb levels  decreasing to 4.2%. Follow-up indicated modifications to prevent future exposures. This case
highlights the diagnostic challenge of CO poisoning in open environments and underlines the  importance of maintaining clinical suspicion despite atypical presentations and the absence  of concurrent symptoms in others nearby. Understanding CO's diffusion dynamics and  potential for significant exposure even in well-ventilated spaces is crucial for timely diagnosis  and management. The findings stress the need for heightened awareness among emergency  responders and healthcare providers to promptly recognize and manage CO poisoning in  diverse environmental settings, ensuring optimal patient outcomes and minimizing risks to
responders.