The circumstances of the one-and-a-half year old boy’s fall are still being investigated by police in the town of Lagos, in the southern Algarve region.
The boy is Portuguese but with British parents who live in Portugal.
He fell on Saturday morning local time.
A spokesman at the Hospital and University of Algarve told Sky News that the child is in the paediatric intensive care unit.
They had also told news website Lusa that his condition “continues to inspire care”.