SOME CHILDREN at Dundalk Elementary School were eating lunch at 9:45 Friday morning.
The fishburgers or cheesesteak subs and the un-air-conditioned cafeteria ensured the youngsters a hot meal.
Principal Beverly Norwood joked about serving brunch. The usual lunch periods had been pushed ahead 90 minutes so that all the children would be fed before they were dismissed at 12:30 p.m. because of the extreme heat.
But neither the heat nor the school closings were joking matters as Baltimore's hottest May on record made school disruptions common.
School administrators weighed the health and safety of children and teachers against curriculum and parental demands, and many parents spent their lunch hours picking up children at schools that dismissed early. ''In today's complex society, these decisions [to close school] are not made lightly,'' said Richard Bavaria, spokesman for Baltimore County schools. The ramifications of sending children home, perhaps on short notice, perhaps without their parents being aware of it, perhaps to locked or empty homes, enter into the decision, he said.
''The ability to notify parents is a big factor'' in school-closing decisions in Anne Arundel County, said Nancy Jane Addams, spokeswoman for that county's schools. Each spring, the schools let parents know that early closings are possible on hot days and tell them where to listen for announcements; some schools also have systems for calling parents. ''We hope that not too many folks are taken by surprise,'' she said.
In the city, the decision to close is made largely on temperature. If it is 90 degrees by 11 a.m., the schools close at 12:30 p.m., and the announcement is broadcast on radio and television, said Bridget Johnson of the Baltimore City Schools Communications Office.
This policy took some parents quite by surprise last week. ''I didn't even realize they would be closing,'' said the mother of a second-grader at Roland Park Elementary School. The woman, who asked not to be identified, was working, without access to radio or television, when the school-closing announcements were made.
Her youngster, who is normally picked up, walked to a nearby bank where his grandmother works and called his mother, who then had to leave her job to get him. She also said she gave a ride to four girls who had been waiting a long time for a bus.
"It's not a very good way to do things," she said of the city school policy.
Youngsters at Roland Park were reportedly not permitted to use school phones to call home, so long lines formed quickly at nearby pay phones. Meg McFadden, president of the school's parent-teacher association, said she knew of one youngster who, instead of standing in line, went to a cool bookstore for an hour before calling home.
Because the girl's mother didn't know that school had been dismissed, she hadn't worried about her child's whereabouts, said McFadden.
''They just release them and tell them if they don't have a ride, they can come back,'' she said. ''I wonder how long we will be able to get away with that before a child is hurt . . . .''
But Johnson said that when city school children are released early, someone stays with them until they are picked up. This policy does not, however, address those who regularly catch buses home.
At Dundalk Elementary, many children called home. Some even checked with their regular after-school programs to be sure they would be operating. ''Some children need to call,'' said Norwood, who praised her staff and student body for using ''excellent coping skills'' in the intense heat.
Even though children may play outside or go home to houses without air conditioning, they are better off than being in a sweltering classroom with many other children, says Lawrence Callahan, superintendent of schools for the Roman Catholic Archdiocese of Baltimore. Catholic schools in Harford County did not close early with the others in the archdiocese because the principals there said ''we can make it through'' and knew that many parents, who work far from the schools, would not be able to pick up children early, said Callahan.
''We did take parents into consideration; we understand it is difficult for parents to make arrangements,'' he said. However, when heat impedes learning and may make children sick, Callahan feels it is time to close schools.
School systems did receive many calls from parents who wanted the schools toclose, said administrators in several school systems. Baltimore County had ''an equal number of calls from parents concerned about children going home alone as from parents who wanted schools let out,'' Bavaria said.
In the city, Johnson said she answered many calls early in the week from parents who wanted their children dismissed. But when schools did let out early Thursday, she received ''no calls.''
Some parents of children at Roland Park made the best of the disruption. When their children's field trip to the zoo was canceled Friday, those who had already taken time off to be chaperons adjourned to a nearby restaurant for a leisurely breakfast.