Putting boiling water directly into the fridge will not make the entire fridge colder. In fact, it can temporarily increase the temperature inside the refrigerator due to the added heat from the boiling water. This is because the fridge's cooling system will have to work harder to remove the extra heat, and it may take some time for the fridge to return to its normal temperature.
Refrigerators are designed to cool and maintain a specific temperature range. When you add hot or boiling water to the fridge, it can cause a localized temperature increase in the immediate area around the container of boiling water. However, this will not significantly impact the overall temperature of the entire fridge.
If you want to cool down the fridge more efficiently, it's best to allow the boiling water to cool to room temperature before placing it inside. This way, you won't introduce additional heat that the fridge has to remove. Additionally, make sure the food or liquid you're placing in the fridge is in a sealed container to prevent any cross-contamination or spills.
Remember that the fridge's cooling system works by removing heat from the interior and transferring it to the outside, so adding hot items directly to the fridge will make it work harder and temporarily raise the temperature inside. It's best to let hot items cool down first before placing them in the refrigerator for optimal efficiency.