Medical illnesses and treatments can cause distress in patients, and medical professionals are very interested in identifying distress quickly to ensure that a patient can receive appropriate support and treatment. Adult patients often use a screening tool known as the Distress Thermometer to indicate the causes and levels of distress they feel. However, little work has been done on how to assess distress in pediatric patients. This study will investigate the effectiveness of the Distress Thermometer as a tool to accurately measure distress in pediatric patients, and determine whether primary caregivers and physicians can also use the Distress Thermometer to accurately gauge a patient s levels and sources of distress. The study will also investigate the effectiveness of the Distress Thermometer compared with other means of measuring fatigue, mood, and pain levels.