COLUMBIA, Mo. -

Mid-Missouri has seen seasonably cooler temperatures this week, but the summer weather can still affect the way drugs react in one's body. 

Both prescription and over-the-counter drugs are sensitive to warmer temperatures and if not stored in the correct environment, they might not be working how they are supposed to.

"The problem is when drugs sit out in the heat like a car that's sealed up we just don't know how hot it gets in there and how those medicines are going to break down," said Pharmacist Bill Morrissey with Kilgore's Pharmacy.

The U.S. Pharmacopeia recommends most drugs be stored at a controlled room temperature, an average of about 77 degrees.

"We typically try to tell people to keep it below 80 to 85 degrees,"said Morrissey.

Even on 70 degree summer days, the inside of a car is often 10 to 20 degrees hotter inside.

This means any pills could quickly lose their potency, and from a consumer standpoint there is often no way to tell.  

"Just to be on the safe side, if it's important enough for you to be taking that medicine, it's probably important enough for you to store it correctly to ensure you're getting the maximum benefit from it,"said Morrissey.

Pharmacists can test drugs that have been left in the heat, but that requires them to be sent off to a lab which Morrissey said is much more expensive than the cost of pills.

Drugs that are the most sensitive to the heat are liquid drugs that require refrigerating.

Others include birth control pills, insulin, and thyroid medicine.

One pharmacist told ABC 17 News mail order drugs, which represent nearly 20% of retail prescription drug sales in the U.S. can be a concern if left in a person's mailbox.

Mailboxes, like cars, can heat up in just minutes.

"It is just kind of a wild card. So the best practice is to not leave anything in the car if at all possible," said Morrissey.