"致死临界温度" can be translated into English as "lethal critical temperature" or "fatal critical temperature".
"Lethal" emphasizes the deadly or fatal nature of the temperature.
"Critical" indicates that this is the threshold or limit beyond which harm or death occurs.
Both expressions are acceptable, and the choice between them may depend on the specific context or preference. In scientific or technical contexts, "lethal critical temperature" is more commonly used.