Infra-red thermography by itself, despite much wishful thinking, will not quantify heat losses, nor is it always cost-effective when used for other purposes, but it does have a place as a useful tool when used with discretion.
Alan J. Van den Berg,
"Infra-Red Is Not A Panacea - Use Discretion", Proc. SPIE 0078, Low Light Level Devices for Science and Technolgy, (27 July 1976); doi: 10.1117/12.954777; https://doi.org/10.1117/12.954777