Infant Shoshin beriberi is an acute life-threatening condition for which the diagnosis is frequently delayed. Therefore, rapid recognition of right heart failure with lactic acidemia is a crucial element in the diagnosis and therapeutic management. We present the case of a 2-month-old girl with bronchiolitis, right heart failure, and lactic acidosis, who quickly and favorably responded to thiamine supplementation. Thiamine deficiency was established through laboratory tests. We present a brief review of the literature with the different thiamine dosages proposed in emergencies and provide an emergency protocol in cases of clinical suspicion, since thiamine supplementation could help to speed up recovery in infants with Shoshin beriberi.