email about bangungot and drinking water

There is an email floating around about the Filipino saying of a cause of death called bangungot.  It refers to dying inexplicably in your sleep.

The email goes. . .

SILENT KILLER:

What you need to know about NIGHTMARE or BANGUNGOT & some realities

Information from a US-based pharmacist

It seems only MALES are afflicted with this.

IMPORTANT:

Never go thirsty when going to bed and be sure you have plenty of water during your 8-hour rest.

Bangungot has killed a male nurse of UERMMH. It is sudden death in
adults which cause them to die while sleeping..

Many theories have been put forward as its cause. However, here is an article which sheds some light to the cause of this malady.