oliver opatz from the charite, we appreciate your insights. and stay cool. oliver: thanks a lot.ou too. brent: we will try to do that. it seems the heatwave could have some dangerous side effects of a different kind, setting off unexploded bombs. in the second world war, the allies dropped millions of bombs over germany. estimates suggest 100,000 of the m never big -- never exploded. many light unexploded under the ground with live fuses. reporter: after the discovery of a mysterious crater in a western german field, it quickly emerged that a world war ii bomb exploded spontaneously. many are wondering if it was due to the scorching summer weather. time and again in germany, unexploded aerial bombs are still being found. usually they are detonated in controlled explosions at special sites like this one in berlin. specialists do not rule out the possibility that heat can trigger the explosion, but they say it is unlikely. >> temperatures play a role, but even so, the release mechanisms spring retains its force for more than 70 years. at some point due to the nature of the material