Patient description: A 3-day-old Asian female infant presents with jaundice that started a day ago. She was born at 38w3d of gestation, after an uncomplicated pregnancy. The family history is unremarkable. The baby is breastfed. Vital signs are reported as: axillary temperature: 36.3°C, heart rate: 154 beats/min, respiratory rate: 37 breaths/min, and blood pressure: 65/33 mm Hg. Her weight is 3.2 kg, length is 53 cm, and head circumference 36 cm. Her sclera are yellow and her body is icteric. No murmurs or any other abnormalities are detected in the heart and lung auscultation. Her liver and spleen are normal on palpation. Laboratory results are as follows: Serum total bilirubin: 21.02 mg/dL Direct bilirubin of 2.04 mg/dL AST: 37 U/L ALT: 20 U/L GGT: 745 U/L Alkaline phosphatase: 531 U/L Creatinine: 0.3 mg/dL Urea: 29 mg/dL Na: 147 mEq/L K: 4.5 mEq/L CRP: 3 mg/L Complete blood cell count within the normal range. She is diagnosed with uncomplicated neonatal jaundice that may require phototherapy.

Clinical trial eligibility criteria: eligible ages (years): 0.0-0.25,  Hypothermia Neonatal Any infant with the following for whom caregiver not available for KMC, or KMC is not adequate (less than 0.5°C/hour rise in temperature): 1. Axillary temperature < 36.5 °C a) If an electric warmer is available and the infant's temperature is < 35°C, then the infant will start by being warmed on the electric warmer until the infant's temperature reaches 36°C, then can start non-electric Infant Warmer use. 2. Infants at-risk for hypothermia (criteria: estimated post-menstrual age of < 35 weeks or current body weight of < 2.5 kg)  Any infant whose family is unwilling to consent to the study. 2. Mothers who are critically ill at the time of infant or deemed not medically stable by nursing staff to be approached for consent. 3. Any infant with a contraindication to KMC (medical instability) and electrical heating source available. 4. Any infant with initial temperature < 35°C and electrical heating source available. 5. Infants requiring phototherapy. 6. Infants with significant skin condition. Stop If an electric heating source is available, the infant will be taken off of the study and warmed with an appropriate source of electric heat if the infant: 1. If an electric heating source is available, the infant will be taken off of the study and warmed with an appropriate source of electric heat if the infant: i. Has temp < 36 °C while receiving maximum non-electric heat exposure and temperature decreases on any measurement ii. Has temp < 36 °C while receiving maximum non-electric heat exposure and temperature does not begin to rise within 30 minutes iii.Has temp < 36 °C while receiving maximum non-electric heat exposure and not heating at a rate of > ½ °C per hour until temperature >36.5°C iv.Has a temperature that falls below 36°C despite maximum non-electric heat exposure Definition of maximum non-electric heat exposure: 1. IW, KMC, hat; if KMC available 2. IW, blanket, hat; if KMC not available 3. Blanket, hat; while seeking caregiver for KMC and/or preparing IW if KMC and IW not available 2. Has temperature > 37.5 °C 3. Is ever considered to be too severely ill by the medical team to be safely cared for in the non-electric Infant Warmer. 4. The warmer will be removed once its temperature drops below phase change temperature as assessed by noting that the material begins to harden and turn white and is no longer warm in area under where baby is lying