Prosecutors in the trial of former Pleasure Ridge Park High School football coach Jason Stinson heard testimony from an expert witness and two doctors from Kosair Children’s Hospital Thursday.Prosecutors called heat illness expert Douglas Casa of Connecticut, who speculated that player Max Gilpin was dehydrated when he collapsed at practice last year from heat stroke. That drew objections from the defense, who contended that Casa was not qualified to offer a medical opinion.Kosair emergency room Doctor Leslie Greenwell later refuted the dehydration claim under questioning from prosecutor Jonathan Heck.Heck: You got a urine sample?Greenwell: Yes.Heck: And what did that tell you?Greenwell: It was…it was not a very concentrated urine, so it suggested he was adequately hydrated."Stinson is charged with reckless homicide and wanton endangerment in Gilpin's heat stroke death.Greenwell says she recorded Gilpin's temperature at 107.4 degrees in the hospital. Casa estimated that Gilpin's temperature reached upwards of 109 degrees during practice.