Generally we think that thermal bottles or soup cups can only be used for holding hot drinks or food, in fact, there is a vacuum layer to separate the temperature between the food or drinks inside. In other words, by separating the temperatures of inside and outside, thermal bottles and soup cups can also hold cold drinks and food.
As the vacuum layer is a critical part of a thermal bottle or soup cup, here are some tips for protecting the layer.
1. Don’t drop the bottle: hitting the bottle to a hard surface will make the air get into the layer. The bottle cannnot keep cold or warm anymore.
2. Don’t remove the sticker at the bottle bottom - the sticker is for protecting the opening of the vacuum layer.
3. Don’t soak the thermal bottle - rinsing the bottle is totally fine. However, soaking it in water will make the water get into the layer.