Before using a glass toy for the first time, wash it in warm soapy water.
To heat it up safely, run it under hot tap water for a few minutes. Never under boiling water or it will damage the crystal. Do not microwave.
For a cooler temperature, use a bucket of ice, or cold water. Just make sure you don't quickly switch from a hot temperate to very cold or the glass could crack.
Alway use lube! Glass toys are compatible with all lubes.
Wash the toy in warm soapy water after use and sterilise with a toy cleaner.