Seasons Adds Freezing, and Heat Lightning Strike is a form of electrocution.
Edit: but the Heat thing is already in there because I would think the heat thing for the summer would be the same as the sauna so its Just Freezing. They also said that the negative uncomfortable buffs will count when seasons come out.
Like from Live Stream, when they did the freezing death, he was already uncomfortable from one of the moodlets so it gave the death moodlet a point boost.