There is no known product or concept called "thermostix." It's possible that you've misheard or misspelled the name.

To help me understand what you're looking for, could you please provide more context? For example:

* Where did you hear this term? (e.g., a website, advertisement, conversation)

* What is it supposed to be? (e.g., a tool, a material, a brand)

* What are you trying to find out about it? (e.g., its purpose, how it works, where to buy it)

With more information, I can try to figure out what you're looking for and provide a helpful answer.