Function check_cooling 

pub fn check_cooling(
    map: &ThermalMap,
    stack: &StackTarget,
) -> Result<(), AnaLowerError>

Judge the CERTIFIED map against the stack’s DECLARED cooling budget: every junction must sit under t_junction_max_c at the stated ambient. The refusal names the hottest node, its tier, both temperatures, and the cooling class — the same program may compile under a stronger class; that verdict belongs to the checker’s map, not the producer’s optimism.