IEC 61300-2-47:2010 details a procedure for determining the suitability of a fibre optic device to withstand the effects of thermal shock. In practice this means a very short change over time between extreme temperatures. The significant changes include the review of the test severity.
DS/EN 61300-2-47:2011 history
2011DS/EN 61300-2-47:2011 Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 2-47: Tests - Thermal shocks