Hi! Prickly heat is alright if your skin can take it. Ice packs on boobs is fine as well. For tiger balm, best to check with gynae? Below extracted from TB’s website.
IS TIGER BALM SAFE TO USE DURING PREGNANCY OR BREASTFEEDING?
Women who are pregnant, think they may be pregnant, or are breastfeeding should consult a medical professional before using Tiger Balm.
https://www.tigerbalm.com/us/tiger-balm-faqs/
Hui Min