Hello Biko, to look frazzled means to look exhausted physically or emotionally or extremely fatigue. You could also say "worn to a frazzle". If you say "burnt to a frazzle " it means sunburnt.

Either very tired or very hot/burnt! I've had a stressful day at work and it's left me feeling a bit frazzled. By the time I remembered about the meat it was frazzled. Examples from www.dicationary.cambridge.org It's the best online dictionary for learners (I think!) Anna www.englishharvest.blogspot.com