Scientists have detected high numbers of heat loving, or thermophilic, bacteria in subzero sediments in the Arctic Ocean. The bacterial spores might provide a unique opportunity to trace seepages of fluids from hot sub-seafloor habitats, possibly pointing towards undiscovered offshore petroleum reservoirs. The findings could also hold important clues for solving broader riddles of bio-geography. The results also point to the potential use of microbes in offshore oil and gas exploration.