Subcutaneous heparin injections are frequently prescribed for the prevention of deep vein thrombosis One of the most commonly encountered adverse physiological responses to this intervention is the formation of a haematoma at the injection site This creates a challenge for the nurse attempting to minimize haematoma formation and/or patient discomfort during the treatment regime The purpose of this study was to determine if the application of ice to subcutaneous heparin injection sites decreases the incidence and size of haematoma formation and/or minimizes patient discomfort The study used a quasi-experimental design with the subjects as their own control A convenience sample of 70 subjects was each given two injections of subcutaneous heparin, 12 hours apart Ice was applied pre- and post-injection to one of the sites Immediately following each injection, the subjects were asked to rate the level of perceived discomfort at the time of the injection using a visual analogue scale Forty-eight hours post-injection, the nurse inspected the injection sites for the presence of haematoma Results showed that when ice was applied there was no significant difference in the incidence or size of haematoma, however, the subject's perception of pain was significantly less