I have seen several comments stating that one should not shower & wash their hair during their first day in Lhasa. Why is this????

Interesting... perhaps so that the Yaks will think that you're one of them?

Your question intrigued me so I Google and found some answers for you:

1/. It is believe that by showering it will give you a cold and a cold is hard to overcome at high altitude.

2/. Also, some believe that by showering it might put a lot of stress on your blood circulation or heart and possibly cause some serious illness.

Couldn't find a respectable health related web site that will support the theory of not showering and the only information were from travel sites.

It sounds a bit like an urban legend. When my wife was at boarding school 40 plus years ago they were not meant to wash their hair at certain times of the month. Re the showering giving you a cold, do they only have cold showers in Lhasa?

The circulation part is correct. Showering is a fairly strenuous exercise on the body. Do not do it during the first day in Lhasa. Avoid even climbing steps or walking fast.

Nothing to do with cold.

On the contrary,a hot shower improves circulation.I see no reason one should'nt shower.Unless there is a religious connotation attached to it.
The 10 days,I spent driving from New Delhi to Leh & back was around the same altitude.Avoid any form strenuous excercise.Acclamatize.Go ahead soak yourself.Use a lot of moisturiser,post shower.

I wouldn't play with my blood pressure first day arriving at Lhasa by plane. For one, hot shower can cause vessels in your body to dilate, and lower overall BP.

I don't know about the route between New Delhi to Leh, but does one suddenly go from low altitude to 3,500m like flying into Lhasa?

Flying from Delhi into Leh is a pretty bad altitude jolt, but just as anecdotal experience, the altitude affected me much more in Lhasa. (And wasn't a problem in Cusco, as I was able to acclimatize gradually rather than flying from sea level to the high altitudes.)

I would choose a bath over a shower on the first day, mostly due to the lethargy that comes from altitude change. (And it's not like these are generally overnight marathon flights; you could always shower/hair-wash before you get on the plane, no?)

It sounds like a cautionary statement so that the newbies don't pass out in the shower on the first day. Probably not bad advice!

Very interesting.... Thanks for all the info

Educate yourself fully about altitude sickness before heading to Tibet. It is nothing to joke about, and you cannot tell how your body will respond in advance. You may be as fit as Lance Armstrong but you can just suffer like many others.

Maybe you are one of the lucky ones like myself - as I suffer zero issue in Tibet - or you can be like one of my travelmates who have to the clinic twice and continue to have headaches for 3 weeks. Even though we do everything together.

We just came back from Tibet with itourstibet last Dec. Our guide there told us that lack of oxygen is always an issue for the travelers. why no shower on the first day is that the water vapor when you're taking shower is easy to make you stifled and hard to breath, which may cause dangerous result.So...I didn't take shower,but I did wash hair. I'm ok for the altitude.