Scientists have identified aerosols in the air we breathe as the most likely transmission route for the new corona virus. Infection rates are significantly higher in enclosed rooms because of air circulation and limited ventilation. While the new indoor air sensor "Febris" does not detect the virus directly, it measures the quality of the air we breathe on the basis of the actual carbon dioxide levels. The higher the CO2 level, the less fresh the air and less ventilated a room becomes. In turn, this raises the risk of contracting the corona virus. When CO2 levels exceed a predetermined limits, the sensor indicates an optical alarm. This allows home owners, offices or schools to set CO2 limits to manage ventilation according to demand. For complete room monitoring, the device also logs the measured CO2 levels, temperature and humidity and regularly sends this data to a central platform for further evaluation.