How are the dangers of illegally entering a country in any way the problem of said country? Like, if someone was trying to break into your house through a back window and wound up stepping into a nest of ground hornets, no one would say it's your responsibility to make sure the non-path to your back window is free of hazards. Does it really need to be stated that countries are under no obligation to ensure illegal routes across their borders are safe?

If they go the route of TX and actively make the area more dangerous, that's an entirely different story. But it's the US/Canada border. In winter. It gets cold. If your strategy for entering a country involves standing outside in Sub-Zero temperatures with inadequate clothing... You need a different strategy.