The same safety considerations that are compelling more bicyclists to don safety helmets are prompting some health officials to urge the use of helmets for such wintertime activities as sledding, skiing and snowmobiling.

Most accidents in these activities occur when someone runs into an unexpected obstacle like a rock, tree or stump. On a sled, where a child's body is prone, the head is typically the first point of contact, notes Longevity magazine.Each winter about 51,000 children age 5 to 14 sustain an accident in a winter sports activity serious enough to require medical treatment, the Consumer Product Safety Commission estimates.