ABSTRACT The prevalence of premature birth and low birth weight (LBW) in Indonesia is still high enough to cause serious concern. Babies with a birth weight of less than 2500 grams are considered low. The quality of the child's growth and development process is disrupted due to the disruption of vital organ functions caused by LBW. Nesting is used to treat LBW. The purpose of this study was to determine whether the prone and nesting positions affect body temperature, oxygen saturation, and pulse frequency of premature and underweight infants. This research was conducted at RSU Dr. Pingadi Medan. This research was conducted in September 2022. The pretest and posttest design of this quasi-experimental study consisted of taking scores before and after treatment. Sampling method with random selection of 15 respondents. Baby scales, thermometers, pulse exometry, and observation sheets are the instruments used. Univariate and bivariate analyzes were used. Body temperature has a p value of 0.18, oxygen saturation has a p value of 0.00, and pulse frequency has a p value of 0.00. In conclusion, nesting or nesting is one of the environmental management development techniques. Keywords: Nesting, Prone, Body Temperature, Oxygen Saturation, LBW ABSTRAK Prevalensi kelahiran prematur dan berat badan lahir rendah (BBLR) di Indonesia masih cukup tinggi sehingga menimbulkan kekhawatiran serius. Bayi dengan berat lahir kurang dari 2500 gram dianggap rendah. Kualitas proses tumbuh kembang anak terganggu akibat terganggunya fungsi organ vital yang diakibatkan oleh BBLR. Nesting digunakan untuk menangani BBLR. Tujuan dari penelitian ini adalah untuk mengetahui apakah posisi tengkurap dan prone berpengaruh terhadap suhu tubuh, saturasi oksigen, dan frekuensi denyut nadi bayi prematur dan berat badan kurang. Penelitian ini dilakukan di RSU Dr. Pingadi Medan.Penelitian ini dilaksanakan pada bulan September 2022. Rancangan pretest and posttest dari penelitian kuasi eksperimen ini terdiri dari pengambilan nilai sebelum dan sesudah perlakuan. Metode pengambilan sampel dengan pemilihan acak sebanyak 15 responden. Timbangan bayi, termometer, eksometri nadi, dan lembar observasi adalah instrumen yang digunakan. Analisis univariat dan bivariat digunakan. Suhu tubuh memiliki nilai p 0,18, saturasi oksigen memiliki nilai p 0,00, dan frekuensi nadi memiliki nilai p 0,00. Kesimpulannya, nesting atau prone adalah salah satu teknik pengelolaan perkembangan peduli lingkungan. Kata Kunci : Nesting, Prone, Suhu Tubuh, Saturasi Oksigen, BBLR