Based on the context and the answer, generate a question. 

Context: It was the Reebok 10 K marathon . I was 6 hours standing up , going from one place to the other , collecting tea / coffee cups , napkins , glasses , garbage , serving drinks . My feet are alright , though they hurt . My face ... oh god MY FACE !

Answer:

They have a sunburn .



What may be the reason why their face hurts ?