On cold days, I like to read a book in front of the fireplace to warm myself up.

On cold days, it's best to warm up with a kotatsu.

On cold days, warm coffee is the best.

On a cold winter night, hot cocoa is the best.

The cold has become severe.

It's very cold today, isn't it?

It's difficult to go outside in this coldness.

This room is very warm.

I could feel warmth in his words.

Nuan is my best friend.