Summarize the following:
Bring outdoor coleus plants inside whenever there is a risk of frost, as a single light frost is often enough to kill the plant. Some coleus plants may even suffer if night temperature are regularly below 60ºF (16ºC). While indoors, keep the plant away from drafts, and stop fertilizing the plant.  During winter, gradually increase the amount of shade the coleus receives, until it is in full shade. Sudden changes can cause leaf drop.  When you bring the plants inside, they will drop a few leaves. This is because they are adapting to the new conditions. For the first few weeks, carefully monitor their moisture, temperature, and sunlight exposure. Mealy bugs are one of the most common pests found on coleus. These appear as tufts of white fuzz on the stem and leaves, and can be wiped off with a cotton swab dipped in alcohol. . Whitefly infestations show up as clouds of small white insects, and/or many white eggs on the undersides of leaves. For outdoor plants, purchase ladybugs or Encarsia species to kill the whiteflies. for indoor plants, hang up whitefly traps or make your own. Most other insects, such as aphids, can be sprayed off with water or wiped off with a cloth. Some pests require more specialized methods of control:  Tiny red "spider mites" can be driven away by increasing the humidity. Place pans of water nearby and mist the affected area lightly. Tiny black dots hovering near the soil are "fungus gnats," which can be dealt with by adding ¼ in (6 mm) fine gravel on top of the soil, or by reducing watering and increasing air flow.  Get rid of slugs by using a barrier of beer or diatomaceous earth, or purchasing a specialized slug control product. Fuzz, black or ringed spots, or other disfigurements are usually the result of fungal disease. Cut off affected leaves immediately, then sterilize the scissors or shears with boiling water or rubbing alcohol to avoid spreading the disease to other plants. Anti-fungal sprays are available at garden supply stores if the disease continues to spread.

Summary:
Keep coleus indoor in cool weather. Kill mealy bugs. Control whitefly infestations Deal with other pests. Prune or treat diseased leaves.