This study described infant/toddler teachers' (N = 106) perceptions of stress intensity and exhaustion (emotional, physical, mental) intensity. We examined the associations between stress and exhaustion and teachers' reports of stress sources and coping strategy use. Using ecological momentary assessment (EMA), teachers from Early Head Start (EHS), EHS childcare-partnerships, or independent childcare programs (Midwestern U.S.) completed twice-weekly reports of: stress and exhaustion intensity; stress sources (workload, children's behaviors, personal life); and, coping strategies (support from colleagues, distraction, mindfulness techniques, reframing). Research Findings: Stress and exhaustion reports were similar to studies of preschool teachers. Workload and personal life stressors were associated with stress and all exhaustion types. Teachers used fewer than two different coping strategies/per reporting day. Only reframing was negatively associated with stress and emotional exhaustion. Teachers reported greater stress at end-of-week than beginning-of-week. Older teachers reported greater stress and emotional exhaustion. Although one-third of teachers reported >4 ACEs, early adversity was not associated with stress or exhaustion. Practice or Policy: We discuss the results relative to the sparse literature on infant/toddler teachers' well-being and suggest areas for professional development supports while underscoring the need for EHS federal policy makers and program administrators to consider how to reduce/streamline workload.