I don't know my neighbours well, but I do know them al lby sight.
Should one of them come and ask if they could shower here because they either had no hot water, or their bathroom was out of commission I would be perfectly happy to let them use my shower, as long as it was at a time that suited me.
Indeed, a couple of years ago, I offered one set of neighbours the use of my toilet when both theirs were blocked - they have small children, so I visualized chaos. They didn't take me up on the offer, as they had a porta-potty.
I would offer the use of my kitchen too (with more reluctance than the bathroom, admittedly) if a neighbour was without means of cooking warm food.