Enbrel must be kept refrigerated. If your room does not have a refrigerator make arrangements with the medical facility to store your dosage. They could also store your equipment unless you are dosing more than once per week otherwise your cabin steward can get you a "Sharps Container".
Lisa is correct in what you need for travel. There are some nice travel packs available for transporting injectable equipment that must be kept cold. Ask your pharmacist or doctor about them.
Take care and have a great trip.