TORONTO - In what's likely an understatement, Justin Saunders says "it's really not fun" to experience the eye-watering, cough-inducing effects of tear gas.

He figures he was tear gassed directly about 25 times during the Quebec City Summit of the Americas in 2001, and even when he wasn't in the line of fire, it was "still kind of everywhere -- it got on everything."

"I noticed it hit my throat first, and it's difficult to breathe. You usually cough. There's a lot of mucus production," recalls Saunders, an organizer with the Toronto Community Mobilization Network.

"If your eyes are unprotected, then that's the next biggest thing that you notice. Your membranes start tearing up and it's difficult to see because there's so much production of that, so usually you have to have it flushed out, or you have to wait for a really long period of time before it calms down."

If police do pull tear gas canisters from their arsenal during protests at the G20 Summit, Saunders and an ad hoc group called Toronto Street Medics that he's helping to organize will be on the ground and ready to help those who are feeling the effects.

They'll be carrying water for flushing people's eyes, as well as first-aid kits with bandages and supplies to tend to anyone who might get injured or feel unwell.

"Just the fact that there might be tens of thousands of people in the streets, you're going to run into people who have health conditions and might need to be attended to for those," he noted.

Likewise, the big downtown hospitals are preparing for what could be an out-of-the-ordinary weekend.

Dr. Howard Ovens, director of the Schwartz/Reisman Emergency Centre at Mount Sinai Hospital, said all hands will be on deck.

"We are hoping that there will be no major incidents that would require health-care intervention, but just in case there are we have reviewed things that we might encounter -- including exposure of people who may be in or near a protest to irritants such as tear gas or pepper spray."

They've gone over how to handle a Code Orange, a situation in which more than the usual response is needed to deal with patients arriving at emergency departments.

Ovens has never treated anyone for tear gas but has seen victims of pepper spray.

"It looks very similar to somebody who's having an allergic reaction ... Their eyes are red and they're sneezing and blowing their nose, and just looking a bit irritated and it settles down pretty quickly. In fact, I've had the experience of walking into the patient's room and starting to sneeze myself because there was still some pepper spray on their clothing."

Over at St. Michael's Hospital, Dr. Glen Bandiera said they're preparing for pretty well anything.

"We're anticipating that we're probably going to see minor injuries, just because lots of people in a small space creates potential for falls and trips and sprains and strains," said Bandiera, the chief of emergency medicine.

"We are under the belief that any sort of crowd control would probably be undertaken with the use of pepper spray ... We anticipate that that will probably be one of the go-to crowd control agents. And we treat it basically the same we would with tear gas."

Bandiera said the effects of tear gas can be felt for 30 to 60 minutes.

"The first recourse is to get as far away from the source as possible, and then the second is to decontaminate oneself, and water is usually very acceptable," he said, adding that it's preferable to remove clothes if they're heavily contaminated.

"If they experience significant shortness of breath, any change in their vision or a lot of pain in the eyes, or if the symptoms last more than 30 to 60 minutes, then it would be appropriate for people to come to hospital to be assessed."

Bandiera said there's a safe secure private area adjacent to the ER where people can be decontaminated.

Meanwhile, there's been a lot of talk that officials might use long-range acoustic devices to disperse crowds. Also known as sonic cannons, the volume can be increased to the point that anyone nearby can't tolerate the noise.

"My understanding is that the capability of these devices is to actually deliver sounds that are enough that they might actually result in some persistent hearing deficits for some individuals, and there have been anecdotal reports of ruptured tympanic membranes," Bandiera noted.

"I think that would be in the extreme. Most of the time I think people would leave the scene long before they would experience any untoward long-standing effects from these things."

Saunders said he expects the LRAD will be the tool of choice for police.

"They'll probably be more interested in using that and less interested in using tear gas in the downtown core, because tear gas can get wafted in the air to various locations where it's not intended to be used," he said.

The sonic device is directional, he said, and can go to the 135-decibel range, which is apparently crossing the threshold of pain.

"So any sort of hearing protection that people can wear would obviously be beneficial although it's really unknown -- because this is a very new device -- what the long-term or even the short-term effects will be for people."

Speaking from experience, he noted that it's difficult to predict what action police might take at any given time.

"It's often not demonstrators who are dictating the course of what a demonstration looks like. It's the police might decide that they want to clear a street, and they'll just go ahead and clear a street, and you know, we just have to be prepared," he said.

Protesters should stay with a buddy in case they need to be looked after, or vice versa, he advised.

Ovens said anyone who's asthmatic should have inhalers with them in case they encounter something that makes them wheeze.

"If they move away from the irritant and take some of their fast-acting puffers, they probably would be fine. And if they didn't get some relief, and they continued to feel wheezing, then of course they should come see us."