the other reply covered the actual ranges and why it’s important, but in case it’s not obvious:

You should never put hot food in the fridge. Particularly food with a lot of thermal mass like a bowl of soup or thick lasagna. While that would cool the food quicker than just leaving it out, the heat you’re adding is going to heat up the other items in your fridge and risk their safety. And since it will all eventually cool back down it will not be obvious what food was at unsafe temps or how long.