With a validated computational fluid dynamics (CFD) program, we investigated the potential for a wide cover type personalized ventilation (WCPV) system to reduce the risk of Sudden Infant Death Syndrome (SIDS) due to thermal stress, rebreathing of expired carbon dioxide and-exposure to airborne pathogens for a sleep infant. The WCPV system was intended to minimize draft discomfort by blowing cooled air upward and then descending uniformly and slowly over a sleep infant's head. Two settings for personalized airflow were simulated: a spreading angle of 75 degrees (WCPV-75 degrees) and 35 degrees (WCPV-35 degrees) above the horizontal plane. Simulations demonstrated that a well ventilated comfort microenvironment could be maintained around the infant's head with air temperature varying between 19 and 22 degrees C and draft rate kept under 15%. For the infant with supine position, the average time for the air from both ambient and personalized ventilations to reach the infant's inhalation decreased by 29.3% with WCPV-75 degrees and 89.0% with WCPV-35 degrees. Moreover, the infant's exposure to the infectious influenza quanta from an adult standing aside the bed decreased by 54.3% with WCPV-75 degrees and 80.4% with WCPV-35 degrees. On the other hand, WCPV-35 degrees could take 90.3% less time to deliver 26.6% more personalized air to the infant. For the infant with face-to-side sleep position, the WCPV would also improve the infant's microenvironment. A smaller spreading angle resulted in a much better performance, while a bigger spreading angle led to a better "wide-cover" effect. (C) 2016 Elsevier B.V. All rights reserved.