Those medications that stop working due to heat exposure do this simply because the heat reduces the potency of the medications. The medication is still there. It’s basically just diluted. If medications become too diluted, the body does not produce the typical reaction to the medication. Hence, the medication doesn’t have the same effects as before and you notice no difference after taking it. This is why medications are typically kept at room temperature or cooler. You don’t want to pay for medications that don’t work. You also don’t want to run the risk of having an important medication become useless. For example, you don’t want a diabetic’s insulin supply to become void. This could be life-threatening. Why Medications Become Altered Medications that are exposed to heat can become chemically altered. If a chemical change takes place, then the result of taking the medication is completely different. For example, antibiotics can cause stomach or kidney damage if they decay in the heat.