Obsessive Compulsive Disorder (OCD) is a condition associated with recurrent intrusive distressing thoughts, images and urges compelling the person to perform neutralizing acts or thoughts to the extent of significantly interfering with their daily activities. The symptoms of OCD are associated with both subjective and objective signs of distress. Treatment for Obsessive Compulsive Disorder is often associated with significant subjective distress with high dropout rates and often only limited improvement. Attempts to reduce distress in anxiety often focus on re-establishing the sympathovagal balance by enhancing the vagal or parasympathetic tone and it has been suggested that this can reduce the mobilization behaviours of fight or flight response and improve emotion regulation. This study will investigate the effect of a procedure potentially reducing distress and improving outcome of treatment in inpatients admitted for treatment for OCD to the Anxiety Disorders Residential Unit. The procedure will be based on increasing vagal tone by application of cold face mask on 3 consecutive days in addition to the standard Exposure and Response Prevention therapy (ERP).