Prolonged exposure to direct sunlight may also discolour or dehydrate turquoise. The diatoms abrade the insects' surfaces, causing them to dehydrate and die. Mucus is able to absorb water or dehydrate through pH variations. The outer epidermis is relatively thin, so hippos dehydrate rapidly in dry environments. Dry and windy environments can dehydrate a corpse, leading to mummification. Another factor is that cold temperatures lead to drier air, which may dehydrate mucus particles. Some foods dehydrate well, such as onions, peppers, and tomatoes. At higher temperatures, ethanol will dehydrate to form ethylene. If there is too little water then tissues will dehydrate and the plant may die. When heated, samples dehydrate to give iodine pentoxide. High winds reduce the humidity, dehydrate the flowers, and affect pollination. Even at high temperatures, solid KOH does not dehydrate readily. Unable to escape the constant airflow, the insects quickly dehydrate and die. The monohydrate is used to dehydrate and remove sulfate from various products. Plants can also dehydrate their cells by moving water into intercellular spaces.