When we talk about someone with respect, it can translate to: He does not feel hot.
Is this invariably about personal perception, or could this sentence be used to talk about something that doesn't seem hot to the touch (albeit with a different pronoun. eg. 'these things')?
Wait for someone who knows what they're talking about to confirm, but I think when using this construction with the verb lagna, garmi, not unhen, is the subject.