If you take one bath a week with water at 10°C, but on the last week you take a 90°C bath, your average over the year is only 1.5°C rise, but you're still dead.

If you take one bath a week with water at 10°C, but on the last week you take a 90°C bath, your average over the year is only 1.5°C rise, but you're still dead. Average is just that. We have a lot of water that is much harder to drastically change the temperatures over, but the land can have wild swings. 2°C of average change is about 10°C swings in temperate climates.