Warmth is analgesic in healthy newborns.

This study identifies a behavioral and nonpharmacologic means of preventing and reducing newborn pain. Our objective was to determine whether warmth is analgesic in newborn infants undergoing vaccination-a routine painful hospital procedure. We used a prospective randomized controlled trial of 47 healthy full-term newborn infants. Infants were randomized into 1 of 3 conditions prior to vaccination: warmth exposure, pacifier suckling, or sucrose taste. Crying, grimacing, and heart rate differences were analyzed between groups before, during, and after vaccination as outcome measures. Warmer infants cried significantly less than sucrose taste or pacifier suckling after vaccination. Heart rate patterns reflected this analgesia. Core temperature did not differ between study groups. Providing natural warmth to newborn infants during a painful procedure decreases the crying and grimacing on par with the "gold" standard treatments of sucrose or pacifier.