Comment by mattkrause

Yup—too much potassium.

Apparently you can (almost) do it unintentionally if you play tennis in the heat—though 88oz (2.6L) seems like a lot!

Here’s a case report:

Hakimian, J., Goldbarg, S. H., Park, C. H., & Kerwin, T. C. (2014). Death by Coconut. Circulation: Arrhythmia and Electrophysiology, 7(1), 180–181. https://doi.org/10.1161/circep.113.000941