Abstract: An infant thermal shield is formed of a bag of a plastic such as polyethylene which is a material of solid monolithic non-cellular cross-section which is adapted for permitting the audio detection therethrough of body functions. The bag is provided with a hoodless neck opening and is furthermore provided with a longitudinal opening of continuous linear form located frontally or laterally with respect to the bag. The bag is furthermore provided with a bottom opening which can be selectively sealed or held in gathered relationship in order to permit the ingress and egress of connections to medical apparatus. A closing arrangement is provided which is preferably formed of strips of pressure responsive material. The material from which the bag is fabricated is adapted for being held in skin tight relationship over limited portions of the infant so as to permit the effective use of the head of a stethoscope or the cuff of a blood pressure measuring apparatus.