If you can't find an electric one or dont want to be tethered to a plug since youre on holiday, the next best thing are those stick on patches. Salonpas makes a heat sticky pad thing that is really strong. I'd imagine most pharmacies around the world will carry something of the sort.
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Ah yes good call, that's prob an easier solution anyway. Will go by a pharmacy tomorrow and give them a google translate 😁🤞