LYNN – Don’t step on the ice unless you know it’s thick enough to support your weight.That’s the precautionary word from the Massachusetts Emergency Management Agency (MEMA), which on Friday issued a list of safety precautions regarding frozen lakes, rivers and ponds.”Before we experience a tragedy that is unfortunately too common this time of year, it’s important that we remind everyone, particularly children, of the dangers of unsafe ice,” said MEMA Director Donald Boyce. “Lakes, ponds, streams and rivers throughout the commonwealth have begun to freeze over, however, the temperature continues to fluctuate above and below freezing, making ice conditions very uncertain. People may be a bit impatient to venture out on the ice for skating, hockey, ice fishing and other winter sports. We highly recommend the use of recreational skating areas provided by your local communities. It’s very important to exercise precaution and common sense.”Boyce stressed that people should check with local police, fire or park departments to ensure that safe ice conditions exist. However, due to the uncertainty of ice conditions and the dangers presented, many departments will not endorse the safety of lakes, ponds, streams or rivers, he said. The strength and thickness of ice should be known before any activity takes place.In Lynn, the Fire Department carries some ice rescue equipment aboard its trucks, including boats, rescue sleds and cold-water immersion suits.”We have the equipment and we train on it,” said Fire Lt. Paul Ricchi. “If there’s an ice call, the companies respond, just as they do if there’s a rescue situation at a fire scene.”Fire Capt. Joseph Zukas, head of the department’s emergency medical services, added that the Fire Department does not routinely check ice for thickness. “People call up all the time and ask us if the ice is safe. The answer is always no. We don’t certify the ice,” he said.Zukas said the two rescue boats are stationed at firehouses on Western Avenue and Broadway.The following are ice safety tips from MEMA:Never go onto the ice alone. A friend may be able to rescue you or go for help if you fall through the ice.Always keep your pets on a leash. If a pet falls through the ice do not attempt to rescue it. Instead,, go for help.Remember that new ice is usually stronger than old ice. As ice ages, the bond between the crystals decays, making it weaker, even if melting has not occurred.Beware of ice covered with snow, which can insulate and keep it strong, but can also hinder it from freezing. Snow can also hide cracks, weak and open ice.Slush is a danger sign, indicating that ice is no longer freezing from the bottom and can be weak or deteriorating.Ice formed over flowing water (rivers or lakes containing a large number of springs) is generally 15 percent weaker.Ice seldom freezes or thaws at a uniform rate. As a result, it can be one foot thick in one spot and barely an inch thick 10 feet away.In an emergency, remember to reach-throw-go. According to Boyce, if a companion falls through the ice and you are unable to reach that person from shore, throw them something rope, jumper cables, tree branch, yard tool. If this does not work, go for help before you also become a victim. Get medical assistance for the victim immediately.If you fall in, try not to panic. Turn toward the direction from which you came. Place your hands and arms on the unbroken surface, working forward by kicking your feet. Once out, remain lying on the ice. Do not stand. Instead, roll away from the hole. Crawl back to your tracks, keeping your weight distributed until you return to solid ice, a self-rescue method developed by the Federal Emergency Management Agency, in conjunction with the U.S. Army Cold Regions Research and Engineering Laboratory, the Colorado State Parks Department, and the Minnesota Department of Natural Resources.The dangers presented by frozen rivers and lakes are emphasized seasonally by public safety agencies, as are remin