What is the situational irony in how to build a fire by Jack London?

The situational irony in "To Build a Fire" occurs when the man underestimates the power of nature and overestimates his ability to survive in the harsh conditions of the Yukon. Despite being warned about the dangers of traveling alone in extreme cold, he ignores the advice and ultimately fails to build a fire, leading to his demise. This irony highlights the theme of man versus nature and the consequences of hubris.