It all has to do with the way the heat is transferred and how accurately you can adjust that. 

The heat comes from an electric heating element that transfers the heat to the water and then the water transfers it to the bottle containing the milk. 

This is where factors such as the starting temperature of the water and the starting temperature of the milk come into play.

The heat distribution in the milk depends on the quantity and distribution of that heat. 

With this type of bottle warmer, it is therefore always advisable to shake the bottle regularly in order to distribute the heat evenly. 

The figures with the temperature setting are an indication. If in practice you find the food too cold or too hot you can deviate from this and set the controller higher or lower.

If you have any additional questions, you can always contact us via this website. 

Please state the question or complaint clearly, so that we can provide you with the best possible service.