This summer has seen the hottest weather since 1976, no doubt we can all remember that.  Also certain is that we have been feeling thirsty, especially after salty food; but reaching for a glass of water may not be because the salt made us thirsty rather than the need to wash away the taste of it.  The German Aerospace Centre set out to discover how much water would be needed on a long space flight, testing the impact of diet on volunteers sealed in a mock up spacecraft for 7 months!  They found that more salt in the diet causes less thirst as it triggers the kidneys to conserve water.  However, salt also stimulates hunger so presumably more food would need to go into space.  Oh well, one thing for sure is that in seven months time WE shall all be complaining about the cold weather.  Sylvia Mountford.