The outer breast plumage temperature of Dippers Cinclus cinclus roosting beneath river bridges was measured using an infra red thermometer over the environmental temperature range -0.8 to + 10.9°C. Plumage temperature was close to and directly related to, the temperature of the birds' surroundings, but significantly higher (ΔT=2.87°C) suggesting slight heat loss across the plumage to the environment. Plumage temperatures were also measured in Dippers held in the hand; they were much elevated over environmental temperatures (ΔT=17-18°C at 0°C), indicating substantial heat loss during handling. © 2004 British Trust for Ornithology.