Some glasses on the market are resistant to high temperatures, others are not, and the heat is poor.
The glass cup has a very low coefficient of thermal expansion, which is about one-third of the usual glass, that is, it is insensitive to temperature, and has no thermal expansion and contraction which is common to ordinary objects, and thus has high temperature resistance and high heat stability.
Do not use tempered glass on the market as a high temperature resistant cup, usually below 70 degrees, and use it with caution. Moreover, some experts said that there is no such thing as heat-resistant tempered glass products or tempered glass products on the market. Don't be misled when purchasing. If it is a heat-resistant glass cup, the cup will usually be marked with corresponding indications, indicating the operating temperature, application range, etc. If you find the nominal heat-resistant glass at the time of purchase, the price is very low, so think about its authenticity.
Glass is a very rigid material with a slow heat transfer rate and a thicker glass. Because of the temperature difference, the temperature rises faster and the crack is easier. That is to say, the temperature difference between the boiling water and the glass is too large to cause the cup to split. Therefore, the thickness of the thick glass is usually "-5 to 70 degrees Celsius". Maybe add some cold water before pouring the water, then add some hot water. When the cup is warm, the water will be drained in the future, and then the water will be added.
Before using the glass, it is necessary to distinguish the operating temperature of the ordinary glass and the high temperature resistant glass, and make a reasonable choice.