Scientists super-heated water to 200°C to observe its state under high pressure.

super-heated 是由前缀 super-（表示"超级、超过"）和动词 heat（加热）组成的复合动词，过去式形式。super-heated 字面意思是"超级加热"，指将物质加热到超过其正常沸点的温度。