It's been very rare over the years for me to be in the house on my own. On one occasion a few years ago when I was, I took the dog for his late-night walk, normally just a brief emptying session. But when I got home I realised I had no keys, and it was midnight, and Not Warm.
There was a spare key 1.5 miles away in Phyllis's house. Luckily, I had a couple of £1 coins about my person and phoned her. She was, of course, already in bed. The dog got a much longer walk than usual that night.