Population 1a: Hospital staff who complete study questionnaires.  Inclusion Criteria:  Nurse or physician fluent in English and employed full-time by the hospital, affiliated practice, or affiliated university who cared for bronchiolitis patients on a unit participating in the trial during at least 5 days of the most recent bronchiolitis season Hospital administrator fluent in English who oversaw the care of bronchiolitis on a local level (e.g. nurse manager) or a hospital level (e.g. Chief Quality and Safety Officer)  Exclusion Criteria:  • Under the direct supervision of study or site principal investigator(s)  Population 1b: Hospital staff who participate in qualitative interviews  Inclusion Criteria:  • Nurse or physician fluent in English and employed full-time by the hospital, affiliated practice, or affiliated university who cared for bronchiolitis patients on a unit participating in the trial during at least 5 days of the most recent bronchiolitis season  Exclusion Criteria:  • Under the direct supervision of study or site principal investigator(s)  Population 2a: Bronchiolitis patients directly observed while not receiving supplemental oxygen ("in room air," for primary trial outcome)  Inclusion Criteria:  Infants and children 2 months through 23 months old Hospitalized on non-ICU wards participating in the trial Cared for by generalist inpatient services (e.g. general pediatrics, hospital medicine) Primary diagnosis of bronchiolitis in most recent physician progress note Not actively receiving supplemental oxygen ("in room air") Last documented receipt of supplemental oxygen >1 hour prior to direct observational data collection  Exclusion Criteria:  Documented apnea or cyanosis during the current illness Extreme prematurity (<28 weeks completed gestation) Cardiac disease Pulmonary hypertension Chronic lung disease Home oxygen requirement Neuromuscular disease Immunodeficiency Cancer Severe Acute Respiratory Syndrome Coronavirus 2 (Covid-19 / SARS-CoV-2)-related illness (known or suspected, including multisystem inflammatory syndrome in children multi-system inflammatory syndrome in children (MIS-C)  Population 2b: Bronchiolitis patients directly observed while receiving supplemental oxygen (for underuse evaluation).  Inclusion Criteria:  Infants and children 2 months through 23 months old Hospitalized on non-ICU wards participating in the trial Cared for by generalist inpatient services (e.g. general pediatrics, hospital medicine) Primary diagnosis of bronchiolitis in most recent physician progress note Actively receiving ≥2 Liters/minute (2L/min) supplemental oxygen or 21% room air flow  Exclusion Criteria:  Extreme prematurity (<28 weeks completed gestation) Cardiac disease Pulmonary hypertension Chronic lung disease Home oxygen requirement Neuromuscular disease Immunodeficiency Cancer Severe Acute Respiratory Syndrome Coronavirus 2 [Covid-19 / SARS-CoV-2 (known or suspected)]  Population 3: Parents or guardians of bronchiolitis patients who participate in qualitative interviews.  Inclusion Criteria:  Their child was hospitalized for bronchiolitis on a unit participating in the trial during the most recent bronchiolitis season Their child was found to be continuously SpO2-monitored while in room air during Aim 1 data collection Fluent in English  Exclusion criteria:  Does not recall being present while child was continuously SpO2-monitored They are an employee of the hospital or a hospital volunteer