Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm characterized by rapid and irregular beating.
Emperor penguins owe their scientific name (Aptenodytes forsteri) to their discoverer, the first natural scientist to reach Antarctica, the German Johann Reinhold Forster. Forster came to Antarctica in 1770, on Captain James Cook's ship, and saved Cook's life during the voyage.
It depends on the species because while the penguins of the Galapagos withstand a warm climate, the Adelie penguins (Pygoscelis adeliae) need low temperatures to avoid fainting; that is why, along with the emperor penguins, they are the only other species who live all their lives in Antarctica.