Sir james dewar reportedly said minds are like parachutes. they only function when they are this

Below you can find the Sir james dewar reportedly said minds are like parachutes. they only function when they are this Jeopardy Words Answer. The answer to Sir james dewar reportedly said minds are like parachutes. they only function when they are this has 4 letters. This clue belongs to the Quotes category and is part of Jeopardy Word Level 82. If you scroll near the bottom you will find other clues and answers part of level 82