Drinking cold water after delivery

Hi mummies, is it true that drinking & eating any thing that is cold after delivery will harm the baby? I had been told by my grandma and nanny that I am not allowed to consume anything cold (even lukewater is prohibited.) Since my LO had turn 1 month few days back. Is it alright for me to consume cold foods & drinks? I went out today for the 1st time after delivery and bought a teh bing & apple juice when I am running my errands. Do I need to discharge my breastmilk for today?