Maintaining neonatal body temperature (thermoregulation), particularly during the first hour after birth, is critical for survival and successful adaptation to the extrauterine environment. Implementation of a thermoregulation bundle is expected to facilitate faster stabilization of physiological parameters and to positively influence the initiation of breastfeeding as well as overall breastfeeding success. The effects of a thermoregulation bundle applied at birth on neonatal physiological parameters-including body temperature, respiratory rate, heart rate, and oxygen saturation-and on breastfeeding outcomes will be evaluated.

Thermoregulation in Newborns and the Care Bundle ApproachThermoregulation is the ability to maintain body temperature within specific ranges despite changes in ambient temperature. Maintaining the newborn's body temperature, particularly within the first hour after birth, is critical for survival and adaptation to the external environment. When thermoregulation cannot be achieved during this first hour-often referred to as the "Golden Hour"-it can lead to adverse outcomes such as hypothermia, hypoglycemia, respiratory distress, and delayed breastfeeding. Preventing neonatal hypothermia in the delivery room stands out as a cost-effective approach to reducing neonatal mortality.Maintaining a stable body temperature is challenging for newborns. They are at high risk for hypothermia due to weak subcutaneous fat tissue, a high body surface area-to-weight ratio, and the immaturity of the nervous and cardiovascular systems involved in heat production. Subcutaneous fat constitutes 2-6% of a newborn's body weight, and they utilize this tissue to maintain thermal balance. Because their surface area-to-weight ratio is significantly higher than that of adults, newborns lose heat four times faster. Hypothermia is an independent risk factor that affects multiple systems and increases neonatal morbidity and mortality. Thermoregulation, which is vital in neonatal care, ensures the maintenance of normal body temperature by balancing heat production and heat loss. The normal body temperature for newborns should be maintained between 36.5°C and 37.5°C. To optimize this, the WHO recommends that delivery rooms be kept between 25°C and 28°C (77°F-82.4°F). Maintaining the room temperature within the recommended range is of vital importance, as the newborn increases oxygen and energy consumption when unable to keep body temperature within normal limits.To prevent hypothermia and support breastfeeding in healthy newborns, the WHO recommends skin-to-skin contact with the mother for the first hour after birth and dressing the baby appropriately for the ambient temperature. This typically means using twice as many layers as an adult, including a hat . The Turkish Neonatology Society's delivery room management guidelines prioritize heating and drying over positioning the head and aspiration. In newborns, a body temperature of $<36.0°C$ is considered hypothermia, while $>38°C$ is considered hyperthermia. According to the World Health Organization's recommendations, the temperature in the delivery room should be between 23-25°C. For term infants, the guidelines suggest drying the baby with warm, dry linens starting from the head, removing wet linens immediately, and placing a hat that covers the ears. Healthy term infants should be placed in skin-to-skin contact on the mother's chest, facing her, with their backs covered by a warm blanket. Unless respiratory support is required, these infants do not need to be placed under a radiant warmer. If respiratory support is provided, ensuring the air is humidified and heated is crucial for preventing hypothermia. The use of radiant warmers for term and preterm infants born with moderate-to-severe hypoxic-ischemic encephalopathy should be carefully evaluated. Furthermore, the Turkish Neonatology Society explicitly states that hot water bottles, surgical gloves filled with hot water, or bags should never be used to warm the baby, as they may cause burns .In a study examining the success of thermoregulation on breastfeeding, it was observed that newborns' body temperatures increased during the nursing process. In the experimental group, infants were breastfed in a room at 22-25°C with reduced clothing (only a bodysuit and diaper), while the control group breastfed in the same room temperature with their existing clothes. The study found that newborns in the experimental group (reduced clothing) breastfed for longer durations on the first day. Interventions to support thermoregulation have been shown to prevent both neonatal hypothermia and hyperthermia. Procedures performed in the first hours after birth must be carried out with correct timing and sequence to support thermal regulation . In the literature, there is a lack of studies examining the effects of a "Thermoregulation Bundle" specifically for term infants. A "Care Bundle" approach involves the simultaneous and complete application of a small set of evidence-based interventions (usually 3-5) that have been scientifically proven to improve patient outcomes. These bundles are typically applied following an "all-or-nothing" rule; if one element is missed, the entire bundle is considered incomplete . A thermoregulation bundle is a cost-effective approach that ensures evidence-based and standardized thermal care after birth. The results obtained from this research are expected to provide evidence for interventions aimed at maintaining newborn temperature in the delivery room, thereby supporting neonatal health and successful breastfeeding.

Inclusion Criteria:

• The baby is born vaginally
• It is a singleton pregnancy,
• The baby is born at term (gestational age 38-42 weeks),
• The baby's Apgar score is ≥ 7 at 1 minute,
• The baby's birth weight is between 2500-4000 grams,
• The baby is exclusively breastfed,
• The baby has no problems preventing breastfeeding,
• The mother has no problems preventing breastfeeding,
• There are no maternal or fetal complications.

Exclusion Criteria:

• The baby being preterm/postterm,
• Starting formula feeding,
• The baby having special care needs (intensive care, etc.),
• The baby having intrauterine growth restriction (IUGR), genetic disease, etc.

The study can be shared by the researcher once it is completed.

Due to the nature of the intervention (thermoregulation bundle applied immediately after birth), blinding of participants, care providers, and outcome assessors is not feasible. Therefore, the study is conducted as open-label