すみません、このホットドッグは温められますか？ — Excuse me, can this hot dog be warmed up? (Convenience · Store, Formal — to staff, JLPT N5)

Gesture & etiquette

Hold up the item you wish to have warmed, make eye contact, slight bow.

Not all items can be heated. Be prepared for a polite refusal (e.g., '申し訳ございません、こちらは温められません'). Do not get angry if an item cannot be heated.