Apart from reducing visibility and disrupting air and road traffic, fog is a major health hazard. It can be especially bad for people suffering from respiratory diseases such as asthma, bronchitis and high blood pressure, etc.
"I'm taking maximum precautions like wrapping myself in layers of warm clothes and eating a balanced diet. But I still need an inhaler because I'm finding it difficult to breathe," said Shivani Parekh, 25, a sales executive.
Doctors ask people to take extra care during winters as fog mixed with pollutants in the air can pose a health risk.
"Fog has suspended particulate matter and oxides of nitrogen and sulphur that can cause difficulty in breathing, blocked nose, asthma, aggravated sinus, etc.," said Dr Neeraj Jain, chest specialist, Sir Ganga Ram Hospital.
Breathing smoggy air can also result in eye, nose, and throat irritation, chronic bronchitis, asthma, and headache. Common symptoms include shortness of breath, difficulty in breathing, cough, bluish colour around lips and nails and dizziness etc. It can also result in reduced lung function that may last for as long as a week.
Children and old people are at higher risk.
"Since it is not practically possible to control the changing climate, one should take as much precaution as possible," said a senior doctor in the department of internal medicine at New Delhi 's Ram Manohar Lohia (RML) Hospital.
If it is necessary to go out during early morning or late evening hours, once should wear heavy woolens. Cold and cough takes longer to recover in this weather so one should not panic and go for self-medication. "Give your body some time to heal, and don't pop antibiotics and steroids without consulting a doctor," said Dr Jain.