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: The patient had a fever ( 38 . 2 degrees C ) , fluctuating blood pressure ( between 165 / 90 and 130 / 70 mg mm Hg ) , and severe extrapyramidal symptoms .
### Output Text:
The patient had a fever ( 38 . 2 degrees C ) , fluctuating blood pressure ( between 165 / 90 and 130 / 70 mg mm Hg ) , and severe extrapyramidal symptoms . 