The accident scene was awash with blood. The twisted metal that was once a pickup truck was crushed underneath a fire truck, and two men were trapped inside.

A veteran firefighter and another worker gingerly lifted a mangled body by its legs and shoulders from the crumpled truck cab and the bloodied seat below.

It could have been just another rescue, another day in which the firefighter was trying to save someone's life. But four days later, Prince George's County officials called to tell the firefighter that one of the crash victims in the July 7 accident on Suitland Parkway had tested positive for the AIDS virus, a disease known to be passed by the mingling of blood.

"I couldn't believe it, to tell you the truth," the firefighter said last Friday, a round gray bruise still visible on his arm three days after submitting to a test for the AIDS virus. "You hear about the risks and all, but you say it won't happen to you."

The 55 other police officers and firefighters who had arrived on the scene that day -- including one who said he had cut himself while helping one of the victims -- were being contacted as well and told that they might want to be tested for AIDS.

The incident, and another like it last month in Baltimore, have raised anew the question of how police officers, firefighters and other public health and safety personnel whose jobs are risky by definition can best protect themselves from an invisible threat such as AIDS while continuing to serve their communities. At the same time, some of the strategies officials are considering could discriminate against AIDS patients and violate their privacy, some civil libertarians argue.

Although health officials estimate that the chances that a rescue worker will contract AIDS from an accident victim are less than 1 in 100, labor unions representing Washington area police and firefighters are calling for more stringent precautions. And although there have been no reports of rescue workers getting AIDS on the job, the fear among such workers appears to be growing.

Policies regarding police and rescue workers' handling of cases involving exposure to blood and other bodily fluids vary in the District and in counties of Virginia and Mary- land. The vast majority of departments, however, have followed the precautions issued by the U.S. Centers for Disease Control in 1985 and equipped their fire trucks, ambulances and police cars with kits containing rubber gloves, plastic masks, paper suits, antiseptic cleanser and goggles.

Most of the departments have advised their employes to use at least the gloves on emergency medical calls, but some are considering making the practice mandatory. The firefighter in the Suitland incident said he and other emergency personnel at the scene were too rushed to put on gloves. His initial test was inconclusive, the firefighter said, and he will have to be retested for the AIDS virus in three months.

Ronald W. Milor, president of Local 1619, the Prince George's County Professional Fire Fighters Association, was among those who in interviews last week dismissed the idea that wearing rubber gloves was enough to minimize the risk of contracting AIDS.

"It's misleading to think that we will be safe simply by putting on gloves," Milor said. "These people get soaked with blood all the way through to their underwear. It gets in their hair and on their arms and legs. You can't just pick someone up and carry them with your hands. Rubber gloves are nice, but they are not the answer to the problem, not with what we have to do."

The firefighter who was involved with the Suitland Parkway accident said that although the incident was his only exposure to a known AIDS patient, it was not the first time he had worried about it. He recalled the case of an attempted suicide last winter.

He and other rescue workers arrived on the scene and found a trail of blood. After breaking down a bathroom door, they discovered a 19-year-old man lying in a bathtub filled with blood and water.

"We reached in barehanded and pulled him out of the water and laid him on the floor," the firefighter said. "The paramedics started working on him, and so I went back into his room. There's this note on the bed in a big pile of blood . . . . At the bottom it says, 'P.S. I'm sorry I'm a homosexual.' I nearly passed out."

Homosexuals are a high-risk group for contracting AIDS.

Last week, the firefighter said, two men were raped by a group of four men. The firefighters who responded to that call "automatically thought AIDS. They didn't want to touch the guys," he said.

"These are the kinds of things going on in Prince George's County, and no one knows about it," he said.

Estimates of the frequency of cases where firefighters and emergency workers come into contact with large amounts of blood vary, but most officials agree that such circumstances may exist about half the time.

For police officers, the risk of exposure is less, with a lot of blood or bodily fluids present in about 20 or 30 percent of the cases they handle, local officials said.

Milor and others concede that bloody automobile accidents, shootings and tussles with drug abusers are part of the territory.

But following the Suitland Parkway accident, Milor and Robert Sappington, president of Lodge 89 of the Fraternal Order of Police in Prince George's, have launched a protest aimed at rescinding a state confidentiality law that forbids hospital personnel from disclosing AIDS virus information about patients. Also, they said they plan to ask the county executive and County Council to introduce legislation that would require hospitals to contact emergency medical workers who might have come into contact with an AIDS patient.

Union officials in Baltimore also criticized the state policy last month when five firefighters and one paramedic who assisted a bleeding, pregnant woman fatally shot by a hunting arrow discovered later that she had been exposed to the AIDS virus.

Fireighters learned of the exposure only indirectly through a hospital employe who recognized her as an AIDS patient.

"We're not going to be able to do anything to make the work we do any prettier, but we'd like to know if we were taking the risk home with us. We owe our families that much," Milor said.

The Maryland General Assembly this year reviewed its policy on when doctors may inform firefighters and emergency medical technicians that they might have been exposed to a patient with a contagious disease.

The law contains a list of six contagious diseases, including hepatitis, tuberculosis, and mononucleosis -- but not AIDS.

Milor said Prince George's firefighters and police officers learned that one of the Suitland victims had AIDS only after a nurse accidentally stuck herself with a needle used on one of the victims.

She requested that the man be tested for AIDS, and when the test was positive, a hospital employe breached the confidentiality law and contacted the county health department "out of professional courtesy."

The American Civil Liberties Union and other organizations have worked to prevent such disclosures. Their members say that while they understand the fears of emergency service personnel, giving out that kind of information could expose AIDS patients and their families to discrimination and harassment.

"I think we all have to take a deep collective breath and see that, in spite of our fears, AIDS can only be transmitted two ways," said Irv Vaid, public information director for the National Gay and Lesbian Task Force. "Those are through intimate sexual contact and some type of exposure to blood that involves some absorption of it. Even so, there have been thousands of hospital workers who have been pricked by contaminated needles and not gotten AIDS."

Still, the fear persists.

"The department has not done enough," said Walter Bader, president of the Fraternal Order of Police Lodge 35 in Montgomery County. "Each officer -- not just each department -- should be provided with the equipment necessary to deal with these cases."

Almost all the police and fire officials contacted last week said their personnel are very concerned about contracting AIDS.

"There is a great deal of apprehension, and a lot of that is due to a lack of education," Bader said. "The department has been very careful to ensure that officers are trained in the best possible methods of handling dangerous situations . . . but this philosophy has not carried over into their policy concerning communicable diseases."

Sgt. Harry Geehreng, public information officer for the Montgomery police, said the department plans to educate its officers concerning transmission of the AIDS virus and the potential hazards involved in handling AIDS patients.

In the District, where firefighters are required -- and police are encouraged -- to wear protective gear where there is a possible exposure to blood or semen, emergency rescue workers have said they should be given greater leeway in being told about health records of the people they help.

"We won't refuse to treat anyone," said Frank Fishburne, president of the union representing the District's Fire Department ambulance workers. "But we also want to be able to protect ourselves."

Firefighters say that the AIDS crisis has added a dimension to a job already fraught with stress and danger.

Workers who are trained to swallow their fears and jump into a situation with a moment's notice say that it has been difficult to condition themselves to pause long enough to think whether the person they are dealing with might have AIDS.

"We haven't developed the habit yet. The instinct is still to get to the scene and react as quickly as possible, not to take the time to throw on the gloves," said Richard McAuley, president of the volunteer firefighters association in Howard County. "Our primary concern, I have to believe, is that we're there to do a job and that's it. If you're concerned about your health to the extent that it prevents you from responding, you should get another job."

Milor and other police and fire officials say they do not know of any colleagues who have quit because they are afraid of contracting AIDS, nor do they believe that the recent accident will encourage anyone to do so.

But according to the firefighter involved in the incident, the accident will motivate him and others to take the time to put on their gloves before they respond to a call, something that few emergency medical workers have done.

"It used to be when you went out on a fire you were trained. If it was a burning building, you knew the floor could cave in. You knew it was dangerous but you were trained to know when it was time to get out," he said.

"With AIDS, you're dealing with something you know nothing about," the firefighter continued. "You can't trust people anymore because you never know."