The big thing about room temp (or less) is the tendency for metal objects to contract/expand due to changes in temperature. If the engine is hot the metal expands and can be harder to remove thus making it more susceptible to breakage.
Ambient air temps in the range your area calls for is just fine for swapping out the plugs with a greater chance of success.
Mac
Ambient air temps in the range your area calls for is just fine for swapping out the plugs with a greater chance of success.
Mac
