This charm can be bestowed by a chwinga living in Icewind Dale or other cold regions by using their Magical Gift action.
This charm allows you to use your reaction when you take cold damage to reduce the damage to 0. You regain a number of hit points equal to half the cold damage you would have taken. Once you do so, the charm vanishes from you.
{
"name": "Charm of the Ice Troll",
"page": 283,
"type": "Charm",
"__prop": "reward",
"source": "IDRotF",
"entries": [
"{@note This charm can be bestowed by a {@creature chwinga|ToA} living in Icewind Dale or other cold regions by using their Magical Gift action.}",
"This charm allows you to use your reaction when you take cold damage to reduce the damage to 0. You regain a number of hit points equal to half the cold damage you would have taken. Once you do so, the charm vanishes from you."
]
}