This week's emergency roster includes an injured scuba diver who must be treated in a hyperbaric chamber, and a youthful gunshot victim. Also, dust explosion results in a serious fire, and danger for victims and firefighter alike. Meanwhile, on the culinary scene, John (Randolph Mantooth) is once again razzed about his cooking skills; and TV personality Chef Mike Roy plays a gourmet cook whose kitchen goes up in flames. ~ Hal Erickson, Rovi