X will let Macy take the water bottle--rather a pokemon the guy trusted than make him uncomfortable. Listening to Nathaniel, he'll nod.

"That's good...do you remember anything? Do you feel hot in anyway? You might need to step out of the light."

Of course, he wasn't a medical expert but he knew well enough it wasn't a good idea to be out under the sun without any protection like this. Plus, there was no telling just how long Nathaniel had been like this before finding him.