Chiller tubes and 15 minutes of boil

Hello, everyone! My second post today. Today i've brewed an IPA, my first ever beer, but in the process i f-ed up a bit. At 15 minutes left to boil i've put my immersion chiller into the kettle to sanitize it, but it began to heat quickly and my tubes, which were attached, collapsed. What tubes should i use for thermal stability and tight connection, so there's no any water leakage? How to connect tubes properly? Chiller is made out of stainless steel, 8mm in diameter.