Getting the lid or simmer ring on can be tricky with a high flame. If you have a Leatherman, the pliers makes an excellent gripper to place it exactly without burning yourself. The simmer ring has a handy tab that can be easily gripped this way. Or, if you use a pot gripper that can sometimes be used too. Or get a couple of sticks to hold it. Otherwise, you can just use your hands - if you do it in a quick decisive action you won't burn yourself.