The UN estimates that about 200,000 Rohingya refugees, including over 100,000 children are threatened by flooding rains.
Cox's Bazar - Nearly one million Rohingya refugees are currently in refugee camps in Bangladesh's Cox's Bazar.
The majority are living in cramped conditions in the Kutupalong-Balukhali, the largest refugee camp in the world.
Children, the elderly, men and women all face difficult conditions in a sprawling temporary city built out of plastic sheets and bamboo.
More than 700,000 Rohingya have arrived since the Myanmar military launched a crackdown on the minority group in August of last year, resulting in what the UN has described as a "textbook case of ethnic cleansing".
Forbidden from building anything resembling a permanent structure, the refugees are huddled on top of each other in this "mega camp". And they're now facing a new crisis: the monsoons.
Bangladesh gets intense cyclonic storms and some of the most intense monsoon rains on earth.
With an estimated 2500mm of rain due to fall over the next few months, parts of the camp are at risk of flooding.
According to UNICEF, about 200,000 Rohingya refugees - over 50 percent of whom are children - are threatened by the anticipated rains.
Some 900 shelters and 200 latrines have already been destroyed, according to figures provided by aid agencies. Water points have been washed away and people have been buried under collapsing mud walls.
Aid groups are trying to move families to safer ground, but with hundreds of thousands of people on site, it is impossible to move them all. And with the inundation, the risk of waterborne diseases such as cholera only grows.