Apart from not wanting to lose precious jewellery, it's a good idea to take it off before you set out on this adventure to walk the Tongariro Crossing.
For me and a few others I spoke to up there, we discovered that our fingers became quite swollen at different stages. Perhaps it was the body dealing or not dealing with pressure changes, but it could be painful if you wear tight rings on your hands.
To alleviate the problem I kept my fingers moving in and out of fist position, and also brought my hands up above the level of my heart to release some pressure. It seemed to work.
Also with all the sulphur around, jewellery can go quite black, sit it's best keep it wrapped and safe.
Please realise that as with most mountains, here in the Tongariro National Park, and especially on the Tongariro Crossing, the weather is fully capable of changing from one extreme to the other, in a matter of minutes.
Here in this photo you can see the lovely blue sky on the left and the approaching cloud on the right. We didn't even see this coming but suddenly could feel the big drop in temperature as the cloud engulfed us. Fortunately on this occassion it passed over and didn't stay. But you need warm clothing to protect you against getting very cold.
29 April 2006 - Two Americans were caught on the mountain when the weather changed, got lost, had insufficient food, water and clothing. Sadly by the time rescuers got to them, the lady had died. The man was very close to succumbing to the horrid hypothermia that took his lady. This happens time and again. PLEASE HEED THE WARNINGS AND GO PREPARED FOR THE WORST WEATHER!
When you find yourself on a scree slope as you do once or twice on the Tongariro Crossing, one way to keep better stability is to remember to walk normally but make sure you put your heels down first and slightly dig them in.
Gravity will provide speed and you find you move quite quickly but maintain the rhythm of heels in first. You eventually find your best style and can maintain balance much easier.