Temps. of infants and children during surgery vary widely and should be carefully watched. Infants under 6 months of age tend to develop subnormal temps. during surgery, which so far we have not found harmful. Fever during surgery developed in over 62% of the children studied in this series between the ages of 6 months and 13 yrs. when not cooled. A cold-water mattress is more efficient than ice bags in preventing fever. Subnormal temps. seem to be beneficial in certain selected cases.