Day care for sick kids? An idea, you'd think, made to order for a workaholic city with enough working mothers to generate the greatest child-care needs in the nation. (Fifty-six percent of area women with children under 6 are employed; nationally, the figure is 45 percent.) But Washington's watching this trend from the sidelines, divided over the idea's wisdom.

"We have been exploring that issue," says Pat Marks, child-care coordinator of the Metropolitan Washington Child Care Network. "A number of employers have asked us to look at it. We've also had some requests from parents."

Part of what makes it "complex," she says, is "the unpredictable nature of illness: you don't know when a child is going to be sick. And when you bring sick kids together outside the home, although it's a solution, it's not ideal . . ."

The care of a sick child is a parent's responsibility, says Celia Boykin, director of the Department of Labor day care center, with about 80 children through age 5. The risk to other children, she adds, outweighs an individual parent's inconvenience.

"This is a risky business . . . I had a child die from Haemophilus influenza (type b) in a center where I was two years ago. In 12 years it was the most devastating experience I had. But it was also comforting to me that we sent the child home. We did what we were supposed to do. You never know. It may be that one case in 1,000. That's why I don't give on health issues. It's just too important."

However, Dr. Karl Hammonds, a pediatrician who acts as consultant to the D.C. Department of Recreation's 19 day care centers, supports the idea of group care for mildly ill children, provided there is medical supervision, physical separation and good hygiene. "Where there is no diagnosis or a more serious illness," he says, the staff should consider removing the child from the center.

Lately, he says, the push for change has been slowed by parental concern about the spread of serious illnesses such as herpes and AIDS. This concern, says Hammonds, has "clouded the picture . . . There's a regressive tendency to say that sick children should not be anywhere in proximity with other children, which I don't really believe."

Family day homes, because they handle fewer children, can sometimes be more flexible about minor illnesses, but they too must comply with local health regulations.

But for most working parents of sick children in the Washington area, there's not much choice: stay home or hire someone else to do it. One area agency charges $5 an hour (minimum four hours) plus $4 transportation to care for a sick child. Another charges from $6.50 to $8.50 an hour depending on the seriousness of a child's illness and the amount of notice given. A $4 transportation charge is added to the lower rate.

Total the costs, says Pat Marks, and you're usually talking "around $9 an hour . . . For most parents, that wipes out their salary or more, so they're going to work that day simply to please their employer . . ."

The one bright spot, observers say, is increasing employer sensitivity. The City of Alexandria, for example, instituted a new policy last July allowing city workers to use their allotted sick leave to care for dependent children or immediate family members living in the same household. It may not solve the problem entirely, but it beats losing pay.