In the scorching heat, worried mothers clutch sick children who are presenting with a mix of maladies – fevers, convulsions, skin lesions and even acute malnutrition.

But this isn't a doctor's waiting room, it's the communal area of a migrant centre in Maicao, a dusty desert city in La Guajira, a region of northern Colombia close to the border with Venezuela.

Each day, dozens of people languish here, just a handful of the estimated three million migrants who have fled Venezuela's long-running economic and political meltdown over the last few years.

The children are here and not in a doctor's office because Venezuelan migrants often don't have the papers to sign up to a Colombian insurer or the means to get to the main hospital which is more than 40 minutes walk out of town under the blazing sun.

Sadly, with the Venezuelan health system short of medicine, supplies or trained staff, this is the next best alternative.

The starkest example of the failings of the two health systems is 38-year-old Luisa*. With 10 other children back in Venezuela, she made the hazardous cross-border journey to San Jose Hospital outside Maicao, on the Colombian side of the border to give birth.