This paper presents a feasibility study of a wearable computing system to protect construction workers from carbon monoxide poisoning. A pulse oximetry sensor has been integrated into a typical construction helmet to allow continuous and noninvasive monitoring of workers' blood gas saturation levels. To show the feasibility of monitoring for carbon monoxide poisoning without subjecting users to dangerous conditions, a prototype for monitoring blood O2 saturation was constructed and tested during a user study involving typical construction tasks to determine its reliability while undergoing motion. As monitoring for O2 and CO simply differ in the number of wavelengths of light employed, if monitoring O2 is feasible, then monitoring for CO will be feasible as well. Using this equivalency, the results of this initial study show that integrating an oximeter into a construction helmet will warn the user of impending carbon monoxide poisoning with a probability greater than 99%. Note to Practitioners-This work addresses the issue of carbon monoxide exposure on construction sites. A noninvasive blood oxygen saturation sensor, called a pulse oximeter, was integrated into a typical construction helmet to investigate the reliability of continuous monitoring of construction workers. The pulse oximetry sensing technology was shown to be reliable under typical construction tasks such that a worker would be alerted of impending carbon monoxide poisoning before becoming impaired. Additional work is required with more complex tasks as well as isolating the sensor from motion artifacts generated by head movement.