Freezing

If a character spends more than 12 hours outside in extreme cold without magical protection, they must make a DC 12 CON save once every hour or take a stage of the Freezing condition, as even warm clothes can protect a person for only so long. If a character is wearing only summer clothes and is not prepared, this check is every 20 minutes. The following effects stack, similar to exhaustion rules
1 The effected creature has disadvantage on all ability checks 2 The effected creature's speed is halved 3 All healing given to the creature is halved 4 The creature automatically fails dexterity checks that involve hands, and it may complete only basic tasks with said hands. 5 The creature becomes vulnerable to fire damage due to being in the cold for so long. If the creature comes within 5 feet of a flame, they take 1d4 fire damage per round spent near it, and they must slowly adjust back into the heat. 6 The creature is unable to think clearly, and concentration on spells is impossible. In addition, the character takes a -4 penalty to intelligence until cleared. 7 The creatures speed becomes 0 8 The creature loses the ability to speak, though telepathy may be used, albeit in a sort of gibberish that only an insane person could conjure. 9 The creature dies