After the blood-pressure lady and the thermometer lady and the height-and-weight lady, after the eye test and the dentist, the end was near.

And that, fittingly, was where they put the immunization station, in a gym-turned-clinic where the prickly issue of proper medical care made its final point.

It was only 1 p.m. yesterday -- the back-to-school health fair was just four hours old -- and 135 children and some teenagers already had gone through half the tests at the Marie Reed Learning Center in Northwest Washington.

This year's fair, which continues today from 10 a.m. to 3 p.m., is expected to beat last year's record attendance of more than 600. Sponsored by the D.C. Office of Latino Affairs and the Commission on Public Health, the free clinic is the city's largest health event.

More than 175 volunteers are taking part. There are 25 doctors, 23 dentists, a few medical interns and more than two dozen nurses, all supplemented by staff workers from the two city agencies. The goal is twofold: to alleviate the backlog in city clinics, which are understaffed and under-budgeted; and to ensure that the mostly Hispanic students are properly immunized against a host of childhood diseases.

"Some of them are coming in for the first time, and they need everything," said physician Mary Ellen Bradshaw, chief of the Bureau of School Health Service, a part of the commission.

Since 1985, the city has required comprehensive medical examinations for all schoolchildren, and the health fair is designed to meet this need. But more and more immigrants living in the Adams-Morgan and Mount Pleasant areas have come to count on the annual event.

"I like it because everything is right here, and they give them all the exams," said Lucia Hernandez, who came here from El Salvador in 1985. Her four daughters, ranging in age from 3 to 12, all went through the myriad tests, which include lab work.

Most of the children, despite irregular or sometimes nonexistent medical care in the past, are quite healthy. The only persistent problem is poor teeth, said physician Denice Cora-Bramble, who works for the commission and has analyzed the medical records from prior fairs.

On the second floor of the learning center, where the dental examinations were held, dentist James L. Matthews said he sees this problem over and over again, although he blames it on the age group. He gives each child, and the parent, a lecture on the merits of fluoride and then slips them a pamphlet promoting dental care.

"We find quite a few cavities, and I see quite a few kids that need orthodontics referral," said Matthews, a volunteer yesterday who finds similar dental problems among his young patients in Southeast Washington.

Ramon Rodriguez, fresh from passing an eye test administered by Bob Webb, sat down in front of Matthews and opened his mouth.

"Right away, I see he's a candidate for braces," he said of Ramon, an 8-year-old whose parents emigrated from Mexico. To his surprise, and that of his mother and 10-year-old brother, Luis, Ramon passed the test.

"No, you don't have any cavities at all. That's great," Matthews said.

"Do I get something?" Ramon asked.

"They have some fruit out there," replied Matthews, who, like most volunteers yesterday, said the reward for helping out is dealing with the children. "Go and tell them you deserve an apple."

"I already ate two apples today," said Ramon, who earlier had pointed out that last year's dentist gave out toothbrushes.