What a great idea, Tom and Nick! A harness under a harness. That's a new concept to me. Makes sense. Changing harness for night sleep has always made me nervous, especially on a PortaLedge center hung rig. It made for certain tight muscle groups to the sound of clanking carabiners.

Important points brought up by Jim W, without comment... well here I go again.
Compartmentalization must be avoided at all cost. Climbers should be advised of the dangers of pooling blood, and the contribution that a poor harness (or even the best of harnesses in the worst of conditions) can have in this dangerous health condition. We should take this into consideration in writting our standards, but again, we should be cautious to not limit the use of improvised harnesses and lighterweight harnesses (such as rock harnesses) when climbing will not involve long periods of suspension.

I too climb with a rock harness beneath my Ness saddle while in my hammock. Gymnastics ensue during the change out period, but the safety is there.

Again the following is suggested verbage

==START OF CLIP==
All climbing saddles must be constructed of materials that have a minimum breaking strenght of 5000#, or be tested to show compliance with ANSI A10.14-1991. --EDITORS NOTE-- this will allow folks to use swiss seats, or other inprovised harnesses in appropriate situations (such as wilderness climbs with ladder climbing, and emergency rescue operations, as long as the solution is created using load rated rope or harness)--END NOTE--
Care should be exercised in selection of PPE, especially saddles or harnesses, to take into consideration the amount of time the climber may be suspended. Climbing operations that require periods of time that exceed 1/2 of one hour should indicate the use of a purpose designed harness/saddle to help prevent pooling of blood in the legs.

==END OF CLIP==

Climb Safe!
Icabod

Very good points there, Icabod. I know very little about suspension trauma. It may very well be something that we should mention.

I also agree that flexibility in harness materials should discussed. We could recommend the use of an ANSI harness, but mention the acceptable use of alternative materials, like you did.