The primary advantage of a cool to the touch toaster oven is that the exterior of the oven remains cool even when the oven is in operation. This reduces the chance of people burning themselves on the exterior of the oven while it is heating up or cooking food.
Toaster ovens with a cool touch exterior use insulation to prevent heat from the interior of the oven from radiating to the exterior. Older ovens often lacked this insulation, leading to a safety hazard as the exterior reaches dangerous temperatures. Toaster ovens with a cool touch exterior are safer for anyone who is in the kitchen while the oven is operating as compared to older models, but they are particularly recommended for those with small children. A child may be burned by a hot toaster oven if playing near the oven, or when opening the oven to take food out after it has been cooked.
Burns from a conventional slot toaster are often less of a concern as compared to toaster ovens, as slot toasters typically use less electricity and do not become as hot as toaster ovens. However, many slotted toasters now feature cool to the touch exteriors as well for additional safety.