Women in India are found to be twice as likely to lose babies if they are working in hot conditions
Working in extreme heat can double the risk of stillbirth and miscarriage for pregnant women, according to new research from India.
The others worked in cooler environments, such as schools and hospitals, although some workers were also exposed to very high levels of heat in those jobs too.
India's Mothers: Bearing the Heat.The BBC's global health correspondent Tulip Mazumdar reports from southern India on new research suggesting heat can double the risk of stillbirth and miscarriage.
The study found that women who worked in similar conditions as her were twice as likely to suffer a stillbirth or miscarriage than those working in cooler environments.
The pregnant women in the study in India really are "At the forefront of experiencing climate change," says Prof Hirst, who is a UK-based consultant obstetrician, and Professor of Global Women's Health at medical research organisation The George Institute.
There is currently no official international advice for pregnant working women in the heat.
The safe heat threshold for people doing heavy work is 27.5C WBGT, according to the US Occupational Safety and Health Administration.
"These women often have no choice but to work out in the sun - they need the money," says Ms Shanmugam.
It shows a WBGT temperature of 29.5C - that's above the safe threshold for doing this type of physically demanding work in the heat.
Sumathy had no choice but to continue to work in extreme heat when she became pregnant again within a couple of years of her miscarriage.