Possible Clues:

• One knows by the sound of it how cold this may be
• What a blow that this comes when it's 9 across!
• Sounds as if one knows where this blow comes from
• Nasal eruption due to head cold
• It comes down your nose
• What a blow to see how one gets involved with Zen
• Blowed if one knows where that comes from, by the sound of it
• Blow hot? No, blow cold
• Explosive explusion of air
• That may show how cold it is, by the sound of it