People have started using gas heaters particularly at night to keep rooms warm oblivious to health hazards it poses to human health.

Very few among them are aware of precautionary measures and majority do not care for even if they are known to these precautions.

Scattered incidents of suffocating to death in Pakistan surface every year during winter due to keeping gas heaters on for whole the night even when asleep.

Health experts believe that many deaths and number of complications can be avoided by making public aware of the preventive measures.

Gas heaters emit carbon monoxide directly into the room and increase the level of indoor pollutants which can potentially harm human health including high incidence of respiratory symptoms.

Heater burning consumes oxygen while gas leakage result in suffocation if the romms are not properly ventilated.

Health expert Dr Mohammad Ashraf says that some people are more susceptible than others to suffer health effects of gas heaters such as heart disease patients, asthmatics, children and elderly.

He said Carbon monoxide is invisible, odourless, colourless and tasteless gas, so is difficult to detect. It is highly poisonous and deprives the body of oxygen.

Dr Ashraf said that an individual is rendered completely helpless without feeling the harm thus becoming unconscious during sleep and ultimately die.

"If the level of carbon monoxide in a room goes above the `safe levels', people with heart disease may get chest pain or angina," he said adding smokers with heart disease are particularly at risk. "Young children and the elderly may also be affected."

Ashraf said exposure to high levels of carbon monoxide can cause carbon monoxide poisoning. "Its symptoms include tiredness, shortness of breath, headaches, dizziness, nausea, muscle weakness, confusion etc while exposure to extremely high levels of carbon monoxide can result in death."

He added that many deaths due to carbon monoxide poisoning can be avoided if some simple safety measures are ensured. If the gas leakage

is suspected, extinguish all naked lights and open doors and windows to ventilate the area, turn off all consumer safety shut off valves and report immediately to gas authorities.

Dr Ashraf said that the length of time that gas heater is used should be minimised. "Also check that the heater has a safety system that shuts the heater off when there is not enough gas pressure."

Heaters that are not in a good working order release higher amounts of pollutants.

To a query, Dr Ashraf said that suspected case of gas poisoning should be removed immediately from the source to the fresh air and evacuated to the nearest hospital. "Be careful about using gas heater, especially if anyone has heart disease, asthma, or is elderly."