The field workers head into ‘The City of Devotees’ to research the deadliest childhood illness in the area.
They pass Hindu shrines that are smeared with red dye and covered with bright flags. Traders try to catch passing tourists and young men speed past on motorbikes.
Then we head into the an alleyway, into tight courtyards and warrens of dark homes, where life is as much rural as urban.
Krishna and Prithvi Laxmi - no relation - are working on an ongoing study of childhood malnutrition and enteric diseases in Bhaktapur, Nepal.
Today they are talking to people about pneumonia, the respiratory disease that accounts for 16-18 per cent of deaths in the area’s under fives.
Chamchala Chyatta, a smiling 24-year-old mother of two, shows them her home.
It's typical for the area. The house is almost pitch black in parts despite the late morning sun.
Each of the four stories is just a single bare room with a wooden ladder leading up through the floor to the next level.
Her traditional kitchen has a cooking stove in the corner - and it is these devices that play a major role in the area’s respiratory illnesses.
Krishna and Prithvi are under the supervision of Dr Ram K Chandyo at the Kathmandu-based Institute of Medicine (IoM).
His team has a paper due to be published which shows an association between kerosene use in the cooking stoves and pneumonia.
Now the price of kerosene has gone up and people are returning to solid fuel – wood and residual crops – which has an even greater risk.
Dr Ram said in his experience people use the fuel they can afford, whatever the public health message.
“We can say use gas, it’s a cleaner fuel,” he said, “but they often can’t afford it, whatever we are saying.”
The IoM has 40-45 academics and field workers based at Bhaktapur’s Siddhi Memorial Hospital, a women and children’s hospital run by a not-for-profit NGO.
The doctor’s most common cases are respiratory disorders and paediatrician Dr Abhay Mandal pointed out that parental smoking is also a major risk factor for pneumonia.
During the Nepalese winter nighttime temperatures are well below zero. Central heating is a rare luxury. it’s normally as cold inside as it is outside, so dangerous fuels are also used for heating and lighting.
All these particles add up to a growing health problem.
The UN found strong evidence that indoor pollution causes pneumonia and other acute respiratory infections, killing more than 7,000 children a year.
And a World Bank report found one fifth of all deaths in developing countries are down to climate change, including air pollution.
The poor of the developing world are swapping indoor wood fires in the countryside for the outdoor pollution of big cities, the report said.
The urban poor in places like Bhaktapur face both problems at once.
They get the pollution of the rapidly growing Kathmandu metropolis 10 miles away, and the indoor pollution of cooking and heating styles that are more about poverty than tradition.
Nepal has seen major health improvements - the life expectancy has more than doubled since the 1950s - but the infant mortality rate is still 10 times that of Western Europe.
The Nepalese Government and the Alternative Energy Promotion Centre recently paid for 475,000 mud and brick stoves with small chimneys to take the smoke outside - but there is still work to do.
Chamchala has heard about these stoves but her choices are determined by harsh economics.
“I know a bit about the health problems,” she said. “But we have to use whatever we can afford.”