1. Receive said non-heated sandwich:
note 1: if your package has any holes or openings, this approach may not be optimal.
2. Insure you have been served said sandwich in a sufficiently large dish - the larger, the better:
note 2: if you carry your own sufficiently large heat proof plastic take out container, this method can work as well.
3. Request 1 full cup of hot water and a few extra napkins; optional to request an empty cup.
4. Using the hot water cup, fill the dish or container to a half full level and place said sandwich in the dish with the hot water:
note 3: be sure that a) your tray is sufficiently level or use the napkins to elevate the dish so that it is approximately level, b) avoid dunking or dropping the sandwich into the hot water containing dish to avoid overflow and/or getting wet.
5. Wait approximately 5 minutes before turning over the sandwich to hear the opposite side and wait another 5 minutes. If necessary (for sufficiently cold sandwiches) pour the used water into the optional empty cup and repeat step 4.
6. When judged sufficiently warm, remove the warmed sandwich from the dish and dry off:
note 4: this process will affect the label on you sandwich bag so collector of sandwich bag labels may decide that this is less ok -- consumers choice:
7. Either prior to or after consumption, either pour remaining water back into cup or request FA service to remove dish and water as well as used napkins:
8. Open package and enjoy warm sandwich!
David