Ulcergard: how stringent are those temperature guidelines?

If you have Ulcergard that has spent some number of winter nights at the barn in your tack trunk, do you still use it?

Do you worry that it’s less effective because it hasn’t been stored at the allowed temperatures?

Merial says: Store at 68°F-77°F (20-25°C). Excursions between 59°F-86°F (15-30°C) are permitted.

My vet drives around all winter long with ulcergard in her truck. It gets well below freezing here in the winter, and the truck sits for hours at some places she visits. She sells it without seeming to have concerns.

Thoughts?

If it has changed color to a dark purpley color it is ruined. Does that when too hot. Ask me how I know… :(. I asked the agent when I saw her at regionals last year.