To determine the methods used in veterinary practice to maintain the temperature of intravenous fluids, and the users' impression of their efficacy, data were collected from a survey of 150 veterinary practices. Of the 99 per cent of the practices that warmed intravenous fluids, the use of a heat retention bag cover was most popular and was considered most effective. In a laboratory experiment, four methods of maintaining the temperature of intravenous fluids were compared. The results showed that there was a significant loss of heat through the giving set. A heat retention cover was an effective device for maintaining the temperature of the prewarmed fluid in its bag. The use of ‘hot hands’ (a sealed surgical glove containing warmed water) was most effective in reducing heat loss from the delivered fluid, and was aided by prewarming the giving set.