If you have access to electrical outlets [ I imagine you will ?] then you can bring a light/ heat source and keep it over the temporary enclosure. Bring a few different watt bulbs with you, so you can be ready for lower/ higher temps. If you will be out in full sun and it's hot in your area, you won't need any extra heat, but would need a set up that would allow air flow and partial shade. If you can determine these things the week of the fair, you can plan ahead. I hope your dragon is a friendly one and won't mind the attention !!