The Gough-Joule effect (aka Gow-Joule effect) is the tendency of elastomers to contract when heated if they are under tension. Elastomers that are not under tension do not see this effect.
The effect is important in o-ring seal design, where the seals can be mounted in a peripherally compressed state in hot applications to prolong life. 
The effect is relevant to rotary seals which can bind if the seal shrinks due to overheating.
1. ^ Martini, Leonard J. (1984). Practical Seal Design, P.233. CRC. ISBN 978-0824771669.