Updated 6:37 p.m.
A grandmother, who was healthy, was with the woman and the child. The grandmother was driving the vehicle when the mother and child left the hospital, said Sandusky Police.
Police officers would still like to check on the welfare of both mother and child, officers said.
Original posting below
Sandusky police and area law enforcement are urging the public to be on the lookout for a beige Kia Sorrento with Michigan license plate CJQ 3071.
The woman had brought the child to Firelands Regional Medical Center as both were ill on their way to Cedar Point. Both were treated with oxygen and intravenous fluids, but the woman became dissatisfied and left the hospital with the child before being discharged.
Please call 911 with any information