hello, what is the life expectancy of these extensions, say if worn continuously? how heat resistant are they, like if i were to get close to the oven will they melt? What material are they made of?

Each person is different in their care routine, so its difficult to gauge, but we have several people that are wearing them continuously for over a year. They are moderately heat resistent, not a low temp, but not a high temp fiber - they are a nice middle ground synthetic. They will not melt in a hot tub or being close to an oven, but I wouldn't continuously blast them with heat. If you will be in extreme conditions, I would consider taking one of the dreads and exposing it to those conditions before you are committed to a full head. They can take quite a bit of consistent abuse. I think you will be pleasantly surprised. :)