Head insulation and heat loss in naked and clothed newborns using a thermal mannequin

Abstract

In newborns, large amounts of heat are lost from the head, due to its high skin surface area. Insulating the head (for example, with a hat or bonnet) can be a simple and effective method of reducing dry heat loss. In the present study, we evaluated the safety aspects of insulating the head of low-birth-weight naked or clothed newborns by using a heated mannequin that simulates a low-birth-weight newborn. Experimental conditions (comprising a nude and three clothed setups) were performed in a closed incubator at three different air temperatures (29 degrees C, 32 degrees C, and 34 degrees C) and with and without the head being covered with a bonnet in each case, i.e., 24 experimental conditions in all. The study shows that added clothing elements and insulating the head decreases the total heat loss of the mannequin as a whole. As regards the dry heat exchange from the head, wearing a bonnet decreases the local heat loss by an average of 18.9% in all clothed and thermal conditions. This phenomenon could be at the origin of brain overheating in heavily dressed newborns, when unrestricted heat loss is limited to the face only. Our results suggest that--apart from accidental hypothermia-in order to achieve thermal equilibrium of the body, it is preferable to leave the head unprotected and to increase the level of clothing insulation over the rest of the body.

Assessment of whole body and regional evaporative heat loss coefficients in very premature infants using a thermal mannequin: Influence of air velocity

“…Thus, the present results demonstrate that the head is an important vector of heat exchange with the environment. This has been reported in neonates by Marks et al, 14 Stothers, 15 and by Elabbassi et al 16 using dry heat exchange mannequins. In the present study, we confirm this observation for evaporative heat loss: This is a particularly important parameter in natural convection, i.e., when the speed of air circulating inside the incubator is lower than 0.2 m s −1 .…”

A Simulation Study of Gel Pillow Heat Conductance

“…13 A Topward TPS 4000 variable DC power supply (Topward Electric Instruments Co, Ltd, Taipei Hsien, Taiwan) was used to deliver amperes and volts to the heater wire to heat the mannequin head. The 0.2 ⍀/ft nichrome heater wire was used to heat the mannequin head surface.…”

“…Infants have a larger body surface area in relation to body mass ratio. [12][13][14][15][16] Because the brain accounts for a large proportion of an infant's basal heat production, the skin of the head is always warm, and the heat losses from the head are disproportionately large. Infant skin is more permeable to water and evaporative heat loss.…”

Application of a Thermal Mannequin to the Assessment of the Heat Insulating Power of Protective Garments for Premature Babies

“…The thermal mannequins known so far were suitable only to measure the thermal insulating power. [3,4,[13][14][15] Researchers of the Université de Picardie Jules Verne have assessed the body heat losses between mannequins with small and large body dimensions of premature infants, using two anthropomorphic thermal mannequins of newborns weighing 900 g and 1800 g (Fig. 2).…”