TORONTO -- An expert in childproofing says the freezing death of a Toronto boy highlights the unpredictability of children and the need for caregivers to be prepared for different developmental milestones.

Yehudah Franken says parents can take some simple steps to prevent children from wandering off, such as arming home alarm systems, placing gates at the top and bottom of stairs and adding childproof locks on doors.

"You know they are going to reach these stages, but you don't know exactly when," said Franken, a Toronto-based certified childproofer.

"Don't wait for the child to walk."

Three-year-old Elijah Marsh wandered away from a north-end apartment building early Thursday and was found about six hours later in the corner of a nearby backyard.

Security camera video showed Elijah -- dressed only in a shirt, diaper and winter boots -- pushing his way through two doors and leaving his grandmother's apartment building at about 4 a.m. when temperatures had fallen to about -20 C.

Support for Elijah's family has been pouring in after a Toronto man launched an online fundraising campaign for the boy's funeral. More than $95,000 had already been raised as of Friday afternoon.

There have been other cases of children wandering into freezing temperatures -- some with much less tragic outcomes.

In February 1994, 2-1/2-year-old Karlee Kosolofski was discovered frozen at the door to her home in Rouleau, Sask. Her body temperature was just 14.2 degrees. She had wandered outside and found herself locked out in -22 C weather. Although she lost part of her leg, medical personnel were able to revive her without other ill effects.

In February 2001, 13-month-old Erika Nordby of Edmonton survived with frostbite after wandering into a -24 C night and ending up frozen in the snow.

In December 2009, a seven-year-old Nova Scotia boy died in hospital after surviving two nights lost in the frozen wilderness. James Delorey had apparently followed the family dog into the woods.

Franken said it's more difficult for children to wander out of high-rise buildings because of the many stairs.

He noted that once children reach a certain age, supervision becomes more important than childproofing because children are more capable of figuring the devices out.