Sleep time in ECE rooms for 3- to 5-year-olds has the potential to present emotional and behavioral challenges both for children and their supervising teachers. Currently, there are no studies that have examined this hypothesis; however, two studies have provided indirect evidence for increased stress. Ward, Gay, Alkon et al. (2008) provided preliminary evidence for this hypothesis, with 50% of children (n = 38) observed during sleep time at childcare classified as ‘problem nappers’ (children exhibited disruptive behavior or difficulty settling, requiring teacher assistance). Compared to non-problem nappers, problem nappers had significantly higher levels of cortisol directly following the sleep period. This finding may indicate raised stress associated with an unwanted experience. Additionally, evidence from children's accounts of childcare suggests that naptime is a disliked and unwanted experience for many 4-year-olds. In a study of children's accounts of their experiences in childcare, naptime was named among the top three unwanted experiences alongside “mean children” and” long circle times” ( Wiltz & Klein, 2001). To assess whether such responses relate to the experience of sleep time requires not only an assessment of those who sleep, but also of the experiences of those who remain awake. In particular, documentation of the emotional quality of interactions between children and supervising care staff, and the behavioral management strategies used during the sleep period, is necessary. Further, using measures that allow assessment of the degree of continuity or discontinuity from the emotional climate and behavioral management experienced during all activities throughout the day allows assessment of the independent impact of these factors during sleep time. To this end, identification of a measure suitable for assessment of emotional climate and behavior management within sleep time and during the non-sleep time sessions is required