No, putting a warm bottle of white wine in the fridge will not ruin it. In fact, it is a common and recommended practice to cool down white wine before serving. White wine is best served chilled, as lower temperatures can enhance its flavors and aromas, making it more refreshing.
When you place a warm bottle of white wine in the fridge, it will gradually cool down to the appropriate serving temperature. However, if you need the wine to chill more quickly, you can wrap the bottle in a damp cloth and place it in the freezer for about 15-20 minutes. Just be careful not to forget it in the freezer for an extended period as freezing can damage the wine.
On the other hand, leaving white wine at room temperature for too long can cause it to lose its freshness and potentially lead to premature aging, especially if it's exposed to direct sunlight or heat. So, it's generally a good idea to store white wine in a cool, dark place, and when you're ready to enjoy it, chill it to the appropriate temperature before serving.