Related Clues:

• It's very cold to have to sit around the CIE
• See, senior, never get mostly heated
• I see the ties get knotted when it's very frosty
• At a century of age getting ready for 12 across
• Mostly frees this to make it very hard
• At a century the very aged are very chilly
• Most unfeeling, as a stare
• Most aloof
• Maximally unfriendly
• Most gelid
• Most wintry
• Most frozen
• The most hostile of cities in chaos
• Most reserved box I got for hour after one
• Here is how the French put it, with minimal friendliness