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.