Don't put these things in the thermos

When using insulated cups and kettles in cold weather, it is also important to note that some foods are not suitable for placing inside.
In the past two years, authoritative media have published related events: forgetting to drink red dates in a thermos cup, causing an explosion by unscrewing the cup, and causing the lid to pop, causing the girl's right eye to rupture.
Goji berries and red dates
Soaking red dates, goji berries, and longan in a thermos can easily "explode", but it's actually caused by microorganisms! This is mainly because there are actually many hygiene blind spots in the insulation cups we use, and bacteria may be hidden in the gaps in the inner liner, bottle cap, and other areas.
Dry goods such as red dates and goji berries have rich nutrients, and after soaking in water, the sugar inside is dissolved, making them more easily "utilized" by microorganisms.
When such substances combine with bacteria in the cup, they will ferment and produce a large amount of carbon dioxide and other gases. Over time, the natural pressure inside the sealed cup will increase, leading to an "explosion" that can harm people.
Milk and soybean milk
The reason is that high protein drinks such as soybean milk and milk need to be kept in a sterile or low-temperature environment. And the insulation cup and kettle have not been disinfected and sterilized, nor are they in a low-temperature environment.
The milk and soybean milk in the thermos cup will naturally allow microorganisms to multiply rapidly, which will lead to the acidification of milk and soybean milk and the formation of flocs. If consumed by mistake, it may also cause gastrointestinal discomfort such as abdominal pain and diarrhea.
Carbonated beverages and fruit juices
Carbonated beverages, fruit juices, and some traditional Chinese medicines are mostly acidic and will not cause heavy metal migration when placed in a thermos for a short period of time. But these liquids have complex components and some have strong acidity. Long term contact may cause corrosion to stainless steel, and heavy metals will migrate into the beverage. When using insulated cups to hold gas-producing liquids such as carbonated beverages, be careful not to overfill or shake them violently to prevent the escape of dissolved gases. This can also create safety hazards when the pressure inside the cup increases sharply.
Tea
Parents and teachers who enjoy drinking tea should pay attention to using stainless steel insulated cups to brew tea, which will not cause metal chromium migration or cause corrosion to the stainless steel material itself. However, even so, it is not recommended to use insulated cups to brew tea because tea leaves are usually suitable for brewing. Prolonged soaking in hot water can damage the vitamins in the tea leaves and reduce their flavor and taste. Moreover, if the tea is not cleaned in a timely and thorough manner after brewing, tea stains will adhere to the inner liner of the insulated cup, producing a strange smell.