The Nyrians react to bright light and feel that the ambient temperature on Voyager is too cold, to the point that Chakotay is able to disable several of them in Engineering by turning up the lights, and yet the Nyrian guards in the habitat seem completely unaffected by the bright light there.
The Federation Habitat's climate appears suitable enough for the Humans, with mild temperatures. According to the display on the station's terminal though, the temperature in that habitat is 76C. While the C arguably stands for Celsius, the number is more indicative of a Farenheit scale. However, Tuvok later reads the temperature of the Argala Habitat as "-20 degrees Celsius", and it is fair to assume that the temperatures of all habitats are presented in the same scale. Thus, 76C for the Earth Habitat is clearly mislabeled.