Finally, the lack of artificial heating sources probably kept temperatures relatively cool, which are ideal for quality sleep. (mindbodygreen.com)
The purpose of the paper is to determine whether artificial heat sources have biased the USHCN data. (skepticalscience.com)
Each station was given one of five possible ratings, ranging from most reliable (Rating 1) to least reliable (Rating 5), depending on the distance of the station from nearby artificial heating sources. (globalwarmingsolved.com)