I cringe this time of year when the first major winter storm hits the New York area, like it did last week. I think about the homeless children without warm coats - and about individuals with Alzheimer's disease who become lost.

The risk of becoming lost and the dangers it poses to someone with dementia exist year-round, of course. But during certain weather conditions, this behavior can be even more hazardous: hypothermia during extreme cold weather and dehydration during extreme heat.

It's...