How do lysozymes survive within the human body.

As the title suggests, how do lysozymes survive within the human body? If I'm understanding them correctly, they're one of the enzymes that help fend of all the dangerous things like viruses and bacteria. I remember reading that temperatures of roughly 75C denatures them within a short period of time. If the human body is typically 98.6C, how do they survive? Does your body create enough to counteract the decreasing number of lysozymes?

I could also just be misunderstanding how this functions in its entirety, I apologize in advance if this is way off the mark.