Millions of Canadians are set to be caught under a stifling heat dome, which is expected to linger for days. The dangers and the science of a heat dome, how people are preparing for the abnormally high temperatures, and who could be the most at risk. A prolonged drought in the Northwest Territories means almost the entire area is facing elevated fire danger, including Fort Good Hope, which is only accessible by boat or plane. How a raging wildfire is now threatening the tiny community. With repairs to Calgary's water main break expected to take another five weeks, concerns are mounting about how it could affect the city's lucrative tourist season. The state of repairs, how the Calgary Stampede will still go on despite the water restrictions, and what the city is telling hundreds of thousands of potential tourists. U.S. Surgeon General Dr. Vivek Murthy is calling for tobacco-style warning labels on social media platforms because they have a caused a mental health crisis among young people. Jackson Proskow explains the evidence, and what needs to change. Rehearsals for the opening ceremony of the 2024 Olympic Games are now underway in Paris, which is bucking traditions by holding festivities along the Seine river instead of inside a stadium. The ceremony's unique challenges, the security measures, and the backup plans.