 Warm to 40 degrees to replicate the stifling conditions that Olympians could face in Paris. Because for long-distance runners like Phil, heat has a big impact. Oh, massively. If you're too warm, like you slow down really, really quickly, your heart rate's up high, the effort level is way, way higher. So it's really important to kind of adapt and train that just like you would train your body to run faster. You need to also train your body to run in heat.