极端 (jí duān): 극단적.

On the hottest days of summer, the temperature reached an extreme, and almost no one dared to go outside during the day.

He always goes to extremes: either he works desperately without rest, or he lies around all day doing nothing.

Winter in this region is extremely cold; temperatures often drop to minus thirty degrees, and even the river freezes into thick ice.

His views are too extreme; he completely denies others' efforts, so no one is willing to discuss issues with him anymore.

In the face of extreme weather, the government reminded residents to avoid going out as much as possible and prepared emergency supplies.

Such extremely selfish behavior made everyone very angry, and from then on no one trusted him anymore.