south America and Africa do not extend to the poles, yet parts of these continents experience polarlike climates. Why?

Africa has uplands. South America has both uplands and highlands.

Uplands and highlands have high elevation. Highlands have the variation of polar climates on mountains while uplands have the variation of polar climates on high plateaus.

These are the reasons why some parts Africa and South America experience polar like climates despite not extending to the poles.