A patient in a California ER in 1994 may have had "toxic blood."

Gloria Ramirez was 31 and had cervical cancer. She was rushed to the hospital because her heart was beating too fast and her blood pressure was rising. The staff tried to defibrillate her heart, but when they prepared to, they noticed there was an oily sheen covering her body and a garlicky odor.

When a nurse drew some of Ramirez's blood, she detected a chemical aroma that smelled like ammonia. When she leaned in to smell the blood, she collapsed, and said her face felt like it was burning. Another medical resident that had smelled it also collapsed shortly, suffering from apnea. The third to collapse had no limb control. 

Many more felt sick, and the situation became so desperate that emergency room patients were wheeled out to the parking lot. Ramirez did not live, unfortunately. Her autopsy was conducted in airtight moon suits, and for days nothing peculiar was found. A forensics team uncovered some anomalies, but none that could be linked to Ramirez's death or the symptoms of the hospital staff. In the end, much to the anger of the hospital staff, the state decided their symptoms were merely mass hysteria. 

(Source)