For good sleepers, distal skin temperatures (e.g. hands and feet) have been shown to increase when attempting sleep. This process is said to reflect the body's action to lose heat from the core via the periphery. However, little is known whether the same process occurs for insomniacs. It would be expected that insomniacs would have restricted heat loss due to anxiety when attempting sleep. The present study compared the finger skin temperature changes when attempting sleep between 11 chronic primary insomniacs (mean age = 40.0±13.3) and 8 good sleepers (mean age = 38.6±13.2) in a 26-hr constant routine protocol with the inclusion of multiple sleep latency tests. Contrary to predictions, insomniacs demonstrated increases in finger skin temperature when attempting sleep that were significantly greater than good sleepers (p=.001), even though there was no significant differences in baseline finger temperature (p=.25). These significant increases occurred despite insomniacs reporting significantly greater sleep anticipatory anxiety (p<.0008). Interestingly, the core body temperature mesor of insomniacs (37.0±0.2°C) was significantly higher than good sleepers (36.8±0.2°C, p=.03). Whether insomniacs could have impaired heat loss that is masked by elevated heat production is discussed.