A Vindale cloak, according to its description, protects you from Etherwind when worn. Experience shows that the Ether Disease can still grow worse, but is greatly delayed - the symptoms show a month or more later.
Given that the cloak does not fully prevent the disease, you should still find shelter as soon as possible. It's generally a good idea to reduce the weight of a vindale cloak and carry it at all times. The weight can be reduced by using material-changing scrolls (inferior, change or superior) to roll light materials like cloth, silk or spirit cloth; scrolls of flying can also help, but they are much harder to find and could be better used on other items.
It's not unique and a common item to wish for; it can also be bought from general vendors, though a high shop rank may be needed for the cloak to appear. Also, while extremely rare, it's possible for NPCs and adventurers to get one in their inventory.
It is entirely plausible to get a [Great] quality Vindale cloak if you are lucky. Also, while very rare, it is possible to find <Miracle> quality Vindale cloaks as well.
|It weighs n.|
|It modifies DV by x and PV by y.|
|It protects you from Etherwind|
|Note: Attributes will vary depending on the material.|