# Why do all medicines require storage temperatures below 25 °C?

Almost all medicines I buy have storage requirements saying $T\le25^\circ C$.

But do they really spoil at higher temperatures? What if they are stored at e.g. $30^\circ C$, which is common at summertime?

• As an informal rule of thumb, reaction rates double for every 10 degree C change in temperature. So a medicine at 30C should degrade twice as fast as at 20C. If I had more data to back this up I'd make it an answer, but I don't. Mostly, I think the warning is put there out of an abundance of caution and not wanting to get sued. – user137 Jul 31 '14 at 22:19