1. One may not sit in wet plaster on Yom Kippur.
2. One may not cool off on Yom Kippur by pressing a cup of cold water to his body or by holding it in his hand, because it might spill on him.
3. Young children are not obligated to observe the afflictions of Yom Kippur, with the exception of wearing leather shoes.
4. The Gemara discusses whether a king and a bride may wash their faces on Yom Kippur.
5. There is a similar dispute about whether a woman who gives birth may wear leather shoes.
A BIT MORE
1. This is because the wetness penetrates to his body (even through his clothing) and gives him pleasure as though he is bathing.
2. However, he may hold cool things that do not have water in them in order to cool down.
3. This is because abstaining from wearing leather shoes does not affect them adversely.
4. Tana Kama: They may not. Rebbi Chanina ben Teradyon: A king may wash his face because he represents beauty, and a bride (for thirty days after her marriage) may wash her face so that she not be unseemly to her husband.
5. Tana Kama: She may not. Rebbi Chanina: She may, lest the cold affect her health.