The temperature drop over the last few days means that the season of cold and flu is around the corner.
But this winter comes with additional concerns over a possible surge in other illnesses, including Covid-19.
The country has already been witnessing a spike in the number of coronavirus cases and deaths caused by Covid-19. Moreover, people falling ill from dengue and Nipah viruses are posing new challenges to public health.
Experts said the overlap of Covid-19, flu and other cold-related diseases like pneumonia could complicate the diagnosis and become a burden on the healthcare system.
Covid-19 and the flu are both contagious respiratory illnesses with similar symptoms. Children and elderly people, especially those with preexisting breathing problems, are susceptible to such illnesses due to low humidity, less sunlight, mild vitamin D deficiency and impaired immunity, they added.
The deadly coronavirus would continue circulating in the population if measures like the use of masks, social distancing and screening at airports are not taken properly, they warned.
Practicing the health safety guidelines could limit the flu outbreak, they said.
"Cold-related diseases spike in winter, but this time it is dangerous because of coronavirus since it also attacks the respiratory system," said IEDCR Consultant Prof Mushtuq Hussain.
At least 61 people died of various cold related diseases between November last year and March this year. But the number was only 11 in 2018-19, according to the Directorate General of Health Services (DGHS).
The DGHS has yet to start publishing the data from the current season.
The dengue fever situation is also bad.
This month witnessed the highest number of dengue cases in the year. Usually, dengue cases drop in November.
The number of people infected with dengue this month was 460 as of yesterday, a sharp rise from last month's 163.
Only 47 dengue cases were recorded in September and 68 in August.
The season of mosquito-borne diseases is lingering because of the persisting rainfalls until recently. Such diseases are likely to continue until December, experts said.
Currently, 71 dengue patients are undergoing treatment at different hospitals across the country. Of them, 65 are in 41 public and private hospitals in the capital, according to DGHS data.
A total of 1,087 dengue patients got admitted to public and private hospitals this year. About 1,010 of them had been released. Six suspected deaths were reported, but IEDCR confirmed one.
Meanwhile, Nipah virus has already killed four people this year and the virus will continue to spread until March. Fewer people died with Nipah in the last three years.
The first Nipah case in Bangladesh was detected in 2001 in Meherpur. Since then, cases have been reported almost every year in different districts, according to the DGHS.
A total of 319 people got infected with the virus since 2001 and 225 of them died, the data shows.
There is no vaccine or cure for the illnesses caused by Nipah which has many strains capable of spreading from person to person.
Currently, there are 11,983 beds, of which 555 are in ICUs, in the hospitals across the country. There are 503 ventilators in the hospitals, according to the latest data from the Management Information System of the DGHS.
A total of 24 dedicated Covid-19 hospitals in the country have centralised oxygen supply systems, the data shows.
WHAT EXPERTS SAY
Bangladesh doesn't have the experience of tackling Covid-19 in winter because the disease arrived here in March.
"We see that Canada, many European countries and even the USA are suffering although they are better equipped than us. So it is easily understandable how severe it can turn out to be," Prof Be-Nazir Ahmed, former director (disease control) at the health and family welfare ministry, said.
He added that air pollution increases in winter and those who are asthmatic and have chronic bronchitis might suffer from poor oxygen saturation.
"Hospital admission and death risks will also increase. During this time, cases of pneumonia among kids and elderly people usually rise.
"The government should think of taking preventive measures. Quick tracing is the key to tackle the situation. If we scale up diagnosis at early stages, then we may tackle the situation."
He stressed launching a social movement involving the community, political leaders and public representatives to make people aware of the health rules.
Prof Mushtuq told The Daily Star that: "If we follow the health rules properly, we can avert most of the risks, especially the respiratory problems. The aged and kids have to be aware of pneumonia."
Dr Abul Bashar Mohammad Khurshid Alam, director general of DGHS, said, "There is no doubt that this winter is challenging. We are trying our best to tackle the situation."
DGHS's efficiency has increased and health workers gained experience.
"We hope to tackle the situation. But the health ministry alone cannot handle the situation, people have to come forward," he said, adding that the prime minister herself was continuously monitoring the situation.