Ice crystals are found in several medications during a daily check.

NREMT medication management standards require EMTs to ensure that all medications are stored properly and are safe for administration. The presence of ice crystals indicates that a medication has frozen, which can alter its chemical stability, concentration, and effectiveness.

Option C is correct because medications that have frozen must be discarded and replaced, even if they later thaw. Freezing can cause separation of active ingredients or damage to the medication vial or syringe.

Option A is insufficient because expiration status does not address medication integrity.

Option B is incorrect because frozen medications are unsafe and should not be reused.

Option D is dangerous and explicitly prohibited, as warming does not restore medication safety.

NREMT emphasizes strict medication safety checks to prevent patient harm and ensure effective treatment.