Michael delves into the science of cold water immersion, revealing how just a little bit of physical stress might go a long way to improve your heart health, boost your mood and help keep colds and flu at bay. To find out more, he speaks to Professor Mike Tipton from Portsmouth University who’s been researching exactly what happens in your body when you’re doused with cold water, and why it might have a positive impact on your body and brain, with lasting effects.