Atelectasis as a collapse of lung tissue, atelectasis is not synonymous with a pneumothorax, which is a more specific condition that features atelectasis. Acute atelectasis may occur as a post-operative complication or as a result of surfactant deficiency. In premature neonates, this leads to infant respiratory distress syndrome. The term uses combining forms of "atel-" + "ectasis", from , "incomplete" + ἔκτασις, "extension". May have no signs and symptoms or they may include: It is a common misconception that atelectasis causes fever. A study of 100 post-op patients followed with serial chest X-rays and temperature measurements showed that the incidence of
Cold and heat adaptations in humans to having more cells, and have a smaller surface area compared to smaller individuals, which reduces heat loss. A study by Frederick Foster and Mark Collard found that Bergmann’s rule can be applied to humans when the latitude and temperature between groups differ widely. Allen’s rule is a biological rule that says the limbs of an endotherm is either shorter in cold climates or longer in hot climates. Limb length affects the body’s surface area, which helps with thermoregulation. Shorter limbs help to conserve heat, while longer limbs help to dissipate heat. Marshall T. Newman argues that this can be