"Alas, regardless of their doom,

"The little victims play!"No sense have they of ills to come,

"Nor care beyond today."

He is 3 years old, wearing a red T-shirt and boasting how his dad had taken him to see the fireworks. His little sidekick sucks on a Popsicle and shows off his purple tongue.

"You can't get me, Daddy," shouts one of the boys as he races playfully down the hallway of the hospital wing.

The illness that put them there is masked by their innocence and perfectly normal ways.

They are the children of AIDS.

Not all are so free to run and play. Some come into the world prematurely and drug-addicted. Many have swollen glands, sometimes enlarged livers and spleens. Their bodies are wracked by diarrhea and nausea, burning with fever and wet from night sweats.

More than 500 of them across the United States have died of AIDS and 3,000 are infected, according to Dr. James Oleske, medical director of the children's AIDS program at Children's Hospital in Newark, N.J.

Their numbers are growing at an alarming rate in a nation ill-equipped to care for them; in many places, hospitals must serve as expensive baby sitters while foster homes are desperately sought for the infants.

Dr. Martha Rogers, chief of pediatric and family studies for the AIDS program at the federal Centers for Disease Control in Atlanta, estimates about 10,000 children under the age of 13 will be infected with the AIDS virus within a few years.

That's the low end of Oleske's estimate; he foresees 10,000 to 20,000 infected children by 1991. "I estimate that one in every 10 to 15 hospital beds for children in the United States will be occupied by a child sick with (AIDS) infection. That is a frightening statistic."

About 13 percent of the child victims got AIDS through tainted blood transfusions.

Almost all the others, however, were doomed before birth, born to mothers infected with the AIDS virus through intravenous drug use or through sex with a drug user. Six out of 10 of these children die by age 2 or 3, Oleske said.

The tragedy is compounded when the mother is a single parent and unable to care for the infant because of her drug habit or because she is incapacitated with AIDS herself. A grandmother may care for both, watching both daughter and grandchild deteriorate and die.

With family members unavailable to help in many cases, "Where are the increasing numbers of children born with AIDS going to be cared for?" Oleske asked. "Who's going to care for them?"

One answer may lie in the establishment of state-supported transitional group homes that provide temporary care for outpatient children until foster homes can be found. Several have been set up in the last 18 months, including homes in Boston, Albany, N.Y., and Elizabeth, N.J. More are being planned.

At Boston City Hospital, a renovated wing known as Dowling 5 South can house four children. Among current residents are the two boys whose fathers cannot care for them full-time but who take them on outings like the Fourth of July fireworks.

Since the Dowling wing opened in February 1987, the mothers of two children living there have died.

"Give me two weeks," pleaded one mother _ and she held on long enough to make arrangements for the care of her child.

Anne Murphy, a 31-year-old social worker at Dowling 5 South, has seen dying mothers "just coming in and spending time with their kids, playing with them, putting them to bed, feeding them supper, some of the daily routine kind of things that I think take on so much more meaning when you feel that your time could be limited."

For many of the chidren, however, the warmth of mothers and fathers is absent, and nurses try to comfort them when they cry out with withdrawal pains.

Some of the older children, unable to understand what is happening to them, turn to their toy doctors' kits and play out their own tragic lives.

"They give us fake shots and take our blood pressure," said Murphy. "They play out a lot of the things that happened to them in the hospital . . . and kind of deal with the experience removed from it in a way."

Many potential foster parents are reluctant to consider children with AIDS _ fearful or ignorant of the disease or unwilling to commit the extraordinary amount of time and energy required.

Even so, seven children from St. Clare's Home in Elizabeth, N.J., have been placed in foster homes, said Terry and Faye Zealand, who founded the place of transition between hospital and foster care in May 1987. They plan to open two more homes in New Jersey.

"I can't find a cure for AIDS. I know that I have to leave that up to somebody else, but I know that I can provide a home for these children," Mrs. Zealand said.

In Elizabeth and Albany, townspeople have been sympathetic.

Local construction workers helped renovate a two-story residence that had been vacant for two years for St. Clare's Home. At a zoning board hearing in Albany, three neighbors spoke in support of the Farano Center for Children, which opened in December. Civic organizations held fund-raisers and donated furniture to the home operated by Albany Catholic Charities.

At the Farano Center, as many as 40 volunteers take the children for walks and visits to the park. Three of these volunters have become foster parents to AIDS children, and the applications of four others are being considered.

The transitional homes can accommodate only a half-dozen or so children at a time, cared for by an around-the-clock staff.

That leaves hospitals as the only home for many children of AIDS. That is costly not only to them, in terms of childhood joys missed, but also for the state. Each AIDS child's hospital stay costs an average $650 a day because of the extra nursing care and therapy required. This compares, for example, to $240 a day at St. Clare's.

Some of these kids have never played with a dog or felt the sunshine.

"Everything is a sense of wonder or awe for these children," said Sister Maureen Joyce, who runs the Farano Center. "I was planting some flowers and brought kids out with me. They sat and felt the grass. I had them help me plant flowers. They were so excited."

Mrs. Zealand recalled a 4-year-old whose only playground was the corridors of the hospital until she moved into St. Clare's.

"I can't begin to tell you the experiences she had, swinging on the swings in the backyard, going to the parks and the playground," said Mrs. Zealand. "These are the things all kids need."