In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: CONCLUSION : In patients with FHF and cerebral edema from acetaminophen overdose , prolonged therapeutic hypothermia could potentially be used as a life saving therapy and a bridge to hepatic and neurological recovery .
### Output Text:
CONCLUSION : In patients with FHF and cerebral edema from <span class="chemical">acetaminophen</span> overdose , prolonged therapeutic hypothermia could potentially be used as a life saving therapy and a bridge to hepatic and neurological recovery . 