It seems this is a quote from Wild Thing, by Josh Bazell. I have not personally read this book, and so cannot confirm beyond what a quick lookup told me. Cheers.

if you're going to nitpick then make sure you're not technically incorrect.
You're talking about the SI system, which is a metric system but not the metric system.

Quoth wikipedia (yes wikipedia isn't a source, but i'm not the one who started nitpicking so i don't have to be nitpick proof :^)
"... metric system refers to ones that standardise a set of base units and a nomenclature describing relatively large and small quantities using decimal-based multiplicative unit prefixes (such as kilo and milli). The International System of Units (SI) is a good example, and there are other widely accepted systems (less popular than SI) mainly used in specific fields, such as the Gaussian units for electromagnetism."

How did you calculate the required energy from freezing to boiling? Specifically which boiling point and what heat capacity function did you integrate?