In episode 3, characters recount an instance in the past where a dog that is only mentioned in this scene was shot because of a misunderstanding. Skipping over this scene (19:22-20:20) will not impact your understanding of the story.
In episode 1 a teenager dies of hypothermia out in the woods. It's a very significant event, and the story focuses on both his death and the grief of his family and friends.
In episode 1 a character is mentioned as having died of a combination of falling and hypothermia. Falling being a leading cause of death is also mentioned in episode 1.
In episodes 1 there is underage alcohol abuse, and in episode 4 one character is briefly mentioned to have been an alcoholic and another drinks frequently but it is not known whether this is to an extreme