When the American's and Russian's both set off nuclear bombs at the same time the earth is knocked off its axis and starts moving towards the sun and so temperatures rise. This is good sci-fi born out of cold war paranoia. Unusually for this period the newspaper men question the information coming from the government and the military. The effects are limited, but this is more about the characters which even manage to involve a romance as the world heads towards destruction.
3/5 
Leo McKern
Edward Judd
Janet Munro
Michael Goodliffe
Reginald Beckwith