If someone had explained the definition of brumous as relating to his heart, he might have nodded and said, yes. Yes, that fits.

People speak of the brain as the grey matter, but his brain was active, alight with thoughts and considerations, plans and schema.
Whereas his heart had not done anything besides keep erratic time these past 28 years, like a tired clock someone had neglected to wind. No, winter had settled there, winter and never christmas, like in that story he read so long ago, before everything grew cold, and he despaired that spring might ever return.