After intrauterine life, intensive care is a stressful environment for newborns who have to start their lives in the NICU. Many care practices in the NICU, including environmental factors (such as light, sound), heel prick blood collection, routine care, invasive interventions and bathing, are sources of stress for newborns. At the same time, the physical structure of the NICU, that is, factors such as sound, light, odor, and the physiological and anatomical immaturity of newborn babies, routine care and invasive procedures can reduce the comfort of the baby. Controlling the factors that may cause stress in the infant in the NICU and reducing stress and increasing comfort at the same time may affect the baby's healing process and discharge process.

Recently, nursing care practices that reduce stress and increase comfort are at the forefront and have become an important concept today. In the literature, massage, kangaroo care, swaddling, listening to the mother's voice, listening to music, positioning, mother-scented hand simulation, breastfeeding, wrapping, bathing . Neonatal bathing is among the practices frequently performed by neonatal intensive care nurses to reduce the stress of the newborn and increase comfort Bathing is a basic skin care process for newborns. Bathing is known to have beneficial effects for infants. It is reported that bathing causes relaxation in muscles, is calming and relaxing, is effective in regulating body temperature and reducing pain, regulating blood circulation and respiratory system, and supporting parent-infant bonding (interaction).

Bathing is a basic skin care process for newborns. Bathing is known to have beneficial effects for infants. It is reported that bathing causes relaxation in muscles, is calming and relaxing, is effective in regulating body temperature and reducing pain, regulating blood circulation and respiratory system, and supporting parent-infant bonding (interaction). Bowles (2013) found that neonatal bathing exfoliates dead skin cells, re-moisturizes the skin surface, reduces infant stress and agitation to provide comfort, encourages flexion and containment, and eventually provides developmentally supportive care. In the literature, there are many studies showing that bathing is also effective in reducing bilirubin levels in infants hospitalized with hyperbilirubinemia in neonatal intensive care units.

Stimuli such as lighting, noise and pain from repeated medical interventions in the NICU can cause stress in infants. Excessive lighting can cause negative effects such as weight gain disorder, sleep disturbance and stress in infants. Since phototherapy light is not only a source of stress for the baby receiving phototherapy but also one of the important factors affecting the comfort level, the comfort of babies receiving phototherapy should be monitored frequently. The physical conditions of NICUs, physiologic and anatomic conditions of the infants receiving treatment, invasive interventions and care lead to a decrease in the comfort level of newborns. This situation negatively affects the discharge time and recovery of newborns. Therefore, this study will be conducted to examine the effect of bathtub bathing on stress level and comfort in infants receiving phototherapy in neonatal intensive care.

Inclusion Criteria:

• Newborns with a gestational age of 37 weeks and above
• Birth weight of 2500 grams and above
• Having completed 24 hours after birth
• The newborn is hospitalized with a diagnosis of physiological hyperbilirubinemia and is receiving phototherapy
• No accompanying disease
• No accompanying treatment
• Stable physiological parameters (no tachycardia and bradycardia)
• No respiratory failure or distress (respiratory rate between 30-60, not being monitored on a ventilator, oxygen saturation of 90% and above, no need for continuous high concentration oxygen with methods such as Hood, CPAP, etc.)
• The baby is hospitalized during data collection
• The parents are willing for the newborn to participate in the study Exclusion Criteria
• Preterms with a gestational age of 22-37 weeks,
• The newborn has another concomitant disease diagnosis
• Has been wiped or bathed in a tub within the last 12 hours
• Has been hospitalized with a diagnosis of pathological hyperbilirubinemia
• Has been given sedatives and/or muscle relaxants
• The parent does not want the newborn to participate in the study or wants/wants to withdraw from the study while the study is ongoing