Some lower eukaryotes and some prokaryotes can tolerate temperatures close or even above the boiling point of water. Their special ability enables them to survive under the blazing temperature of the equator or in hot springs. In the warm soil of the Yellowstone National Park the fungus, Curvularia protuberata, controls the high temperature tolerance (65°C) of the grass, Dicanthelium lanuginosum, when the fungus harbors a double-stranded RNA mycovirus (Márquez LM et al 2007 Science 315:513).