Is it okay to store my Flonase in a place that often gets very warm?

Store at 86 deg or <. The package insert for Flonase recommends that it be stored "between 4° and 30°c (39° and 86°f)." the medicine may break down faster if it gets warmer than that, especially if it happens for a long time or if it happens often. That means it won't be as effective when used.
No. Medications have specific instructions to keep at certain temperatures. Extreme heat or cold inactivate the medication. Do not keep it in your car! room temperature is best.