Background:Carbon monoxide (CO) is a highly poisonous, odorless, colorless and non-irritating gas. It is formed by incomplete combustion of carbon or carbonaceous material. Because burning under conditions with insufficient oxygen will prevent complete oxidation to carbon dioxide (CO2), carbon monoxide gas will be formed. When inhaled, it will prevent absorption of oxygen by combining with hemoglobin in the blood, forming carboxyhemoglobin, which result in secondary tissue hypoxia and cellular damage, hence the name "silent killer". Objectives:The three main objectives of the study are; (a) Measuring public exposure to CO producing sources among Saudis using social networking, in winter season for the year 2013-2014, (b) Assessing their awareness and knowledge towards the hazards of carbon monoxide (CO) poisoning produced by different means of heating, and (c) Determine the safety precautions applied to that regard. Methods:A cross sectional study was conducted online targeting, sample size of 634 Saudis from age of (16-50 years) who are using social networks, regarding: a) The public exposure to different CO producing sources, b) The public knowledge regarding symptoms, sources and risks, c) The safety precautions followed to prevent unintentional carbon monoxide poisoning Result:Based on our research, more than half of our sample size (53.94 %) were exposed to CO from different sources with difficulty in breathing being the most known symptom chosen by 75.10% of our sample, followed by headache and dizziness being the second with (57.10%) whilst only 11.70% chose seizures, which is the least symptom, selected. CO poisoning resulted in suffocation and death with 89.11% and 59.62% respectively being the most known risks. Burning coal or firewood was the highest selected source of CO with percentage of 88.60% however, only 4.70% thought refrigerators as a