Temperature fluctuations are back to test the residents' immunity as doctors are reporting an increase in viral infections over the past few days.

The high moisture level in the air and variations between day and night temperatures are to blame for the people's discomfort. Like on Monday, the Patna Met office recorded the minimum temperature at 9.5°C and the maximum around 25 degrees Celsius. The relative humidity hovered around 70 per cent, an increase of 10-15 per cent for this time of the year according to Patna Met director Ashish Sen.

Viral diseases, skin and eye infections have gone up for all these factors.

Shrishti Singh (22), suffering from conjunctivitis for the past two days, said: "My doctor told me temperature fluctuations was responsible for my condition."

Sunil Kumar Singh, an ophthalmologist and director of Sanjeevani Eye Hospital, said: "Bacteria and viruses die only when it is extremely cold or warm but the current weather conditions are very apt for germs to sustain. That is leading to the increase in viral cases and infections at the hospitals."

Singh's hospital has been recently flooded with cases of dry eye syndrome, viral and bacterial eye conjunctivitis and contact dermatitis.

"Of the 30 cases I see every day, at least five to six are of dry eye syndrome, viral and bacterial eye conjunctivitis and contact dermatitis. In dry eye syndrome, the patient experiences irritation and dryness in the eye for which a lubricating eye drop should be used. The patient should frequently blink and avoid sitting before computers and laptops for long durations."

Cases of viral and skin infections among children have also gone up, said paediatrician at Patna Medical College and Hospital Nigam Prakash Narayan. He suggested: "Children should be kept well covered in the day time and away from people experiencing viral infections."

Narayan added: "I am getting 20 to 25 cough and cold cases everyday in the outpatient department (OPD) against five to seven such cases around 15 days ago. Five to seven cases of boils are also coming to the OPD. Asthmatic patients are complaining their condition is aggravating in this weather."

City physician Diwakar Tejaswi said people suffering from chronic obstructive pulmonary diseases (COPD) should avoid smoking or sitting in the sun when cold winds are blowing. "They can enjoy the sun's rays if they want but from a shaded area where they can avoid cold winds. COPD patients should also keep their inhalers close," Tejaswi said.

He added: "Warm days and cold nights are the apt atmosphere for a rise in the cases of infections of the upper respiratory tract and chest. This is the reason we are getting more COPD cases."

Bank employee Kiran Sinha (36) said: "I don't carry warm clothes to office because it is so warm in the mornings. When I return home at night, it isn't cold enough for woollens but there is a discernible drop in temperature. My doctor told me that's how I caught my cough."