Chill Factor (1999) on Netflix

Plot summary

Ten years ago an experiment run by Dr. Richard Long on a Pacific island killed eighteen servicemen and a medical assistant. Long now lives in Jerome, Montana, working at the local base, and Tim Mason, who cooks at a town cafe, goes fly-fishing with him. Colonel Andrew Brynner, who was blamed for that experiment and spent ten years in prison, comes out with a score to settle. He assembles a team of mercenaries, among them a woman named Vaughn, and plans to take a volatile blue crystal called Elvis and sell it to the highest bidder. Long has already handed the crystal to Tim, with one condition: it must stay below fifty degrees or it will detonate. Tim forces Arlo, who delivers ice cream, to haul it to Fort Magruder in his truck while Brynner's men give chase.