The hero was identified as Saranyapong Kadnalai, 19, a deliverer for KFC.
Mother Chaowara Khotsamnuan posted on Facebook that she would like to thank the unidentified motorcyclist who rushed her and her 10-month-old baby to the Phayathai Sri Racha Hospital on May 26.
Saranyapong said he was driving his motorcycle to work and spotted the mother and child sitting on the pavement so he stopped to check if they needed help and rushed them to the hospital.
He said he was determined to get them medical care.
Saranyapong said the mother, who lives in Rayong, called him and would visit him on Thursday.