Central 5-HT3 receptor-induced hypothermia is associated with reduced metabolic rate and increased heat loss

► Central 5-HT3 receptors produced stronger hypothermic effect than central 5-HT1A ones. ► 5-HT3 receptor hypothermic effect was due to decrease in metabolism and increase in heat loss. ► Suppressive effect of 5-HT3 receptor on total metabolism was stronger than that of 5-HT1A. ► 5-HT1A receptor hypothermic effect was due to decrease in metabolism only. ► 5-HT3 receptors switched metabolism to prevalent use of lipids.