Just when you thought it was safe to put your arms down, along comes Hug Holiday.

Unlike Hands Across America, Hug Holiday isn't a fund-raiser or even a particularly national effort. Involving few volunteers and a minimal investment, it exists through the enthusiasm of a 53-year-old educational psychologist and a 62-year-old nutritionist.

"I think there's enough good that comes out of this to make it worth the effort we're putting in," says Jim Johnston, president of the National Institute of Nutritional Education in Denver and cofounder with his wife, Inge, of Hug Holiday.

"Our whole basis is that it's more important to give hugs than get them, and there are a lot of people who don't get any," says Johnston. "I hugged a lady last year whose husband had died four years earlier, and she hadn't been hugged since. It was pretty important to her."

The rules are simple: Those who want to get involved make a little heart that says "hug me." This shows they're a player, and they must say, "Today is Hug Holiday, may I have a hug?" It's definitely not a job for the squeamish, but the Johnstons -- who practice for the holiday on each other and unrelated folks all year -- seem to thrive on it.

Hug Holiday, which today marks its fourth appearance, started inauspiciously. The Johnstons were living in Pompano Beach, Fla., and Inge would give clients an encouraging little squeeze after counseling them about their diet and nutrition. Eventually, people started coming by and saying, "I don't need anything, I just want a hug."

"Then we decided we weren't reaching enough people, so we went to nursing homes on Mother's Day and hugged 500 mothers who had no one to visit them," says Inge. "It was so emotional that they just clung to us."

The Johnstons run into three types of people on their hug missions, says Jim: "There are huggers who say, 'What are you doing this for? I know about hugging and I know it's good.' Then there's the group that doesn't want to be held or touched. We don't do too much with them. But most people are in the middle. They don't mind getting a hug, but want to know what it's all about."

Here are a couple things it's all about:

The Hug Hotline. Huggers are supposed to call 303-690-9646 today and record the number of hugs they've given. A trifle optimistically, the Johnstons are aiming for 5 million. Will people tell the truth? Jim is a little shocked. "Huggers don't lie, and they especially don't lie about hugs."

The Hug Holiday Hall of Fame. Included are goal signs for each year, programs, and photos from previous Hug Holidays. Location: the Johnstons' garage in Aurora, Colo.

The Hug Hit Teams, or H-Teams. "This is a group who gets together around the holiday, goes to retirement homes, does some workshops and hugs people," says Jim.

The Hug Holiday Handbook. A planned glossary of hugs. Among the dozens recorded by the Johnstons: the housewife hug (basically simple and short), the bear hug (when a little person disappears into a big person), the A-frame hug (the upper part of the arms and shoulders meet, but everything else is far apart), the popular side-by-side hug (when the hugger has something in his hands or just isn't comfortable), and the self-explanatory patting hug. Average length of all hugs: 3 to 5 seconds.

"They haven't done very many studies in the area of hug hunger," says Jim, "but I think the problems it causes are as important as the problems caused by food hunger."

Johnston isn't too far wrong, according to Blair Justice, a professor of psychology at the University of Texas School of Public Health who has researched stress, coping, child abuse and child development.

"There seems to be something in the biology of the young human organism that requires physical stroking to survive, and certainly to develop healthily," says Justice. "In homes where this is missing, the central nervous system and neurochemistry does not always develop properly, and the child does not grow physically, emotionally or mentally as well as he should."

With adults, he says, the demand for physical contact like hugging isn't always as great because they depend on another kind of stroking -- verbal. But some adults will prefer negative physical strokes over none at all. "One way they do that: arranging to get hit."

Justice adds that hugs in general are "highly desirable and health-promoting," a conclusion that Leo Buscaglia has been promoting so enthusiastically he's earned the nickname Dr. Hug. ("It's taken me years to live that down," he says. "I'm a legitimate man, I have a doctorate.")

If it were up to Buscaglia, he'd have every day declared Hug Holiday.

"We're supposed to hug each other only this Monday?" he asks. "Like we're supposed to love mother only on Mother's Day? I'm delighted that they're doing it, but it's the other 364 days that are important."

Buscaglia grew up in an Italian family where "it was a sin for anyone to come in the door without giving them a hug." A teacher for 30 years and a full professor for 16 at the University of Southern California, he realized that the bundles of scholarly papers he was producing were unimportant when a young student of his committed suicide.

"Someone was clearly not communicating with her," he says. To get his message heard, he switched tactics. Now he writes best sellers with titles like Love, Personhood, Loving Each Other, Because I Am Human and Living, Loving and Learning.

"We make too much of hugging," he says. "It's become a strange behavior, rather than the norm. It's simply another way of making human contact, of saying 'I care' without having to verbalize it. We're never reticent about hugging a dog or a cat. But if you pet a friend, someone is likely to misinterpret it."

And watch out for those huggers who take his name in vain, saying it's all right to embrace indiscriminately "because Buscaglia says so."

"People can sense when someone's hugging to communicate person-to-person, or if they want some sort of cheap thrill," he says. "When you sense the second, it behooves you to make a comment."

*This is the kind of hugging he thinks is important: "When you come home at night, it's awfully nice to have someone put their arm around you and say 'I missed you.' That doesn't entail any sexual innuendos."

Actually, hugging is very often a sexual means of communication, says Adrian Forsyth, a biologist at Queen's University in Kingston, Ontario, and author of A Natural History of Sex.

"It's difficult to disentangle the sexual element," he says. "If you're an attractive woman and you allow a man to hug you, you can't expect them to react to it as simple affection, irrespective of your relationship."

The origins of hugging, Forsyth speculates, were "parents carrying their infants, feeding them and keeping them warm with an embrace. So it begins as a pleasant experience and continues as an expression of affection."

Embraces are also typical of the displays used by animals to indicate trust or even submission. "For a wolf to offer its throat to another wolf is a signal of complete submission, a way of saying 'You've beaten me entirely and I'm no threat to you whatsoever,' " he says. "Hugging is the same kind of thing."

Forsyth notes that studies done with monkeys indicate that "when infants are deprived of physical contact with their mother, they become neurotic. The same could be true of humans. If you look at societies where there are large, strong families, like in Latin America, there's a lot of physical contact and hugging between family members, and people do seem more easygoing."

Jim Johnston has his own theory about why hugging is unfashionable in this country.

"The Judeo-Christian ethic is not a hugging kind of ethic. And the English, whose stock a lot of us stem from, are nice people, but they're not particularly friendly."

When the Johnstons are asked what they're going to do with all the hugs they plan to collect today, they have a standard answer: "We say, 'It's already been done,' " says Jim. "As soon as the hug is exchanged, the good in it is done."

Everyone has the right to be asked, he adds, and everyone has the right to turn it down. "But people should risk a little. Try a hug, and see if it's as bad as you thought.

"This is the only arms race we all can win."