Swaddling, ie, wrapping the child to restrict movement, is an ancient practice. In the Netherlands, it is becoming increasingly popular as an intervention for excessive crying in infants. However, one must be well aware of the potential risks. We present the case reports of a twin boy and girl who had been swaddled and kept in a heated room for several days. On admission to the hospital, both infants suffered from severe hypovolemic shock, hyperthermia, and secondary respiratory insufficiency. The girl developed multiple organ dysfunction syndrome and died, whereas the boy had an uneventful recovery. When swaddling is being considered as an intervention for excessive crying in infants, parents have to be well-informed about the possible side effects and about additional measures that they may have to take to make it a safe intervention.