Faced with an alarming increase in the use of synthetic marijuana, NYPD Commissioner William Bratton and his top commanders are cautioning officers that they need to be prepared to handle the extremely agitated and delirious people who abuse the substance.

In a meeting of NYPD police executives at the police academy last Monday, as well as another of Bratton's top commanders at police headquarters on Tuesday, officers were told about reports of combative users of the synthetic substance. Users sometimes think they have superhuman strength and seem impervious to pain, said a high-ranking police official familiar with the briefings.

"It is called excited delirium syndrome," said the official, describing a period of extreme excitement characterized by elevated body temperatures, hostility and what one police report said was "exceptional strength and endurance without apparent fatigue." The high body temperatures sometimes prompt users to disrobe in public.

Side effects include increased heart rate, hallucinations, paranoia, anxiety, seizures, loss of consciousness and possibly death, said an advisory from the New York City Department of Health.

Late Thursday five men checked into Manhattan hospitals with symptoms of abusing the synthetic substance, which is designed to produce the effects of regular marijuana use, NYPD spokesman Stephen Davis said.

Possession of synthetic pot isn't covered by penal law, although city health regulations penalize its sale, Davis said.

Known by the popular brand names of "K2" and "Spice," synthetic marijuana has been banned from sale in the city since 2012 but can still be found in some bodega's, primarily in East Harlem, Upper Manhattan and parts of Central Brooklyn, according to police. In recent weeks City Council speaker Melissa Mark-Viverito, a Democrat whose district has been hit with the problem, teamed up with the NYPD to go after retail outlets selling the substance,

"It is prominently showing up in homeless shelters because it is cheap," Davis said.

Bratton said city hospitals are experiencing more than 100 emergency room visits a week because of the synthetic pot. A recent law enforcement intelligence report said there were more than 120 such visits in one week in April alone and one day that month 40 emergency room visits in the Queens-Nassau County border were traced to a synthetic cannabinoid brand known as "Spice."

A special NYPD tactical bulletin circulated this month said that cops should quickly control excited drug users and move them away from other people or objects that could be used as weapons. If necessary, stun guns should be used to incapacitate unruly users. Officers also are being advised that sirens and lights may agitate an already excited drug user.

Police have to recognize its physical and psychological affects and may have to take users to hospitals as quickly as possible.