Definitely a lot of water, hiking shoes, windproof jackets, bug repellent, a change of clothes, and a waterproof bag preferably. This varies depending on the time of year.
I would not put a heating mat underneath, as the snake wouldn't be able cool itself if it needs to. It's important to provide your snake with options to meet...
One drill you could work on with this individual is dribbling. Start by having them dribble while stationary in their chair, then slowly integrate movement by having them roll forward...
They don't need to be refrigerated if they are kept in an air-tight container. If they are not stored in an air-tight container then refrigerate them. If taking them on...
I say you should use only one, especially if you don't have enough money for two. Just wash them thoroughly after every use so your makeup doesn't mix!