If you are a child who is home alone and someone knocks on the door, what do you do?

If you hurt yourself, or the lights go out, what do you do?

Strangers at the door, injuries or household emergencies can be threatening and potentially dangerous to thousands of "latchkey" children in the Washington area who are home alone.

About 20 girl scouts and eight of their mothers got answers to these questions on a recent Saturday when they attended a two-hour "Home Alone" workshop sponsored by the Greater Southeast Community Hospital.

"Teaching kids is your primary responsibility as parents, but parents often don't know what they're supposed to be teaching," said Sallie Eissler, 31, a child-health specialist who taught the course.

Eissler said that she started the program in October after a rash of child molesting incidents had occurred at schools in this area.

Eissler teaches the course twice a month at the Fort Washington Ambulatory Care Center, as well as to interested groups elsewhere.

In Maryland, an estimated 300,000 children between the ages of 6 and 14 have parents who work, according to the Prince George's County Mental Health Association.

As many as 42,000 children in Prince George's public school children -- or more than a third of the county's public school pupils -- are latchkey children, the association estimates.

Eissler began one recent session in the District by giving the girl scouts, who ranged in age from 6 to 17, a test to find out how they felt when they were home alone and how much they already knew about taking care of themselves and their siblings when their parents were away.

"When you're home alone, how do you feel?" Eissler asked.

"Scared!" came the answer in unison.

Sheree Harris, 9, said, "When people come to the door, I get scared sometimes because they are weird people I don't know."

Eissler advised, "Look through the peep hole, and if there is no peep hole, they are easy to put in." And she added: "There are some people you can let in and some you can't. Talk to your parents about it."

Later, Eissler emphasized that an unsupervised child should never open the door to strangers, even if the door has a chain lock.

Call the police if the person does not go away, Eissler said.

"What do you do for a burn?" Eissler asked.

"Put butter on it," several of the scouts answered.

"No," Eissler said shaking her head. She explained that the salt in butter irritates the burn.

"Go over to the sink and run cold water on it," Eissler said. "This cools off your skin so the burn doesn't get worse, and makes it hurt less."

If the lights go out, Eissler told the girls never to light a candle because it could start a fire. Use a flashlight instead, she said.

Eissler has made up her own first aid and emergency kit for use by children who are left alone.

The kit consists of a large plastic bag that contains a flashlight with bulbs and batteries, soap, Band-Aids, an "Ace" bandage, a pillow, a plastic bag in which to put ice, a transistor radio with batteries, and an envelope with taxi money or bus fare.

Erica Bigelow, 11, and her sister Kimberly, 9, said that they had learned a lot from the workshop about how to handle injuries.

Both said that, for one thing, now they know how to care for a broken arm or leg with a pillow and a bag of ice until help arrives.

Each of the girls received a board on which to write important names and telephone numbers for emergencies, and several recipes for food that they could "cook" without a stove.