As the planet heats up, the number of days where the temperature reaches 50C has doubled since the 1980s, global BBC analysis has found. The BBC's Life at 50C season, produced by BBC News Arabic documentaries, set out to find out the impact of this on people living on the front line of climate change. Now, BBC teams in Mexico, Iraq, India and elsewhere tell the story of how they overcame the challenge of filming in such heat.