Assessment of dry heat exchanges in newborns: influence of body position and clothing in SIDS

A dramatic decrease of sudden infant death syndrome (SIDS) has been noted f ollowing the issuance of recommendations to adopt the supine sleeping posit ion for infants. It has been suggested that the increased risk could be rel ated to heat stress associated with body position. In the present study, th e dry heat losses of small-for-gestational-age newborns nude or clothed wer e assessed and compared to see whether there is a difference in the ability to lose heat between the prone and supine positions. An anthropomorphic th ermal mannequin was exposed to six environmental temperatures, ranging betw een 25 and 37 degreesC, in a single-walled, air-heated incubator. The magni tudes of heat losses did not significantly differ between the two body posi tions for the nude (supine 103.46 +/- 29.67 vs. prone 85.78 +/- 34.91 W/m(2 )) and clothed mannequin (supine 59.35 +/- 21.51 vs. prone 63.17 +/- 23.06 W/m(2)). With regard to dry heat exchanges recorded under steady-state cond itions, the results show that there is no association between body position and body overheating.