PRONE SLEEPING INFANTS HAVE A REDUCED ABILITY TO LOSE HEAT

The heat loss coefficients of a group of infants have been calculated and compared to see if there is a difference in the ability to lose he at between prone and non-prone sleeping infants. For a group of 43 inf ants aged 4-29 weeks, a simple mathematical model of exponential cooli ng in a body has been fitted to the fall in rectal temperature which o ccurs in infants at bedtime, One of the parameters yielded by the fitt ing process is the coefficient of thermal heat loss, After validation against the estimated heat loss from supine sleeping infants, the heat loss coefficient was compared at different sleep positions and gender . The mean heat loss coefficient, measured from the non-prone sleeping infants (0.269 W/degrees C, S.D. 0.197) agreed well with the value ca lculated for supine sleepers with the same tog levels (0.4 W/degrees C ), Prone sleeping infants were found to have a considerably smaller he at loss coefficient which was approximately 60% of the value for non-p rone sleeping infants (P = 0.000097). Female infants were found to hav e a heat loss coefficient that was approximately 70% of that of male i nfants but this gender difference was only significant (P = 0.025) for non-prone sleeping infants. These results suggest that infants sleepi ng in the prone position may be unable to lose heat as rapidly as thos e infants sleeping non-prone.