I know this isn't knitting but you could probably adapt it because they're so easy to do. I just happen to crochet as well so it was easier for me to make them that way.I use mainly cast iron pans and the handles can get pretty hot! So, I found a handle cozy online somewhere and did an already created pattern. I also have lids though and my larger pans have an assist handle opposite the regular handle; both of which get hot too. So I came up with a simple pattern for that myself.
Oh, and I don't use anything but cotton yarn for this! An acrylic will melt so please don't use it! I just used Lily Sugar and Cream and it worked fine.
The pattern for the handle cover can be found here. You can make it to fit your handle by adjusting the length (obviously!) It's just basically a square with the edge and one end stitched closed so you could adapt it for knitting easily. It would be best to use a smaller needle to get a tight gauge. The denser the fabric the less heat is going to get through to you. :)
The assist handle mit is just a rectangle with the two ends folded up and stitched down. I crocheted so I chain stitched until I had it as wide as I wanted then I just single crocheted (sc) until I had a long enough piece that I could fold up the ends on it. With knitting you would cast on however many you want for the width then knit until it's long enough to fold the ends up. For mine I sc the edges down but with knitting I would think a simple whip stitch would work fine. If you will be turning it inside out to hide your seaming just be sure to make it wide enough to account for the seam allowance. You just slip your fingers in one pocket and your thumb in the other to pick up your lid or grab the assist handle. Here is the lovely and talented Arielle demonstrating...