Hamish:
[...]
> band 6 temperatures do not look very plausible (30 degC ocean and -6 degC
> land) on a sunny autumn day.
here
<http://landsathandbook.gsfc.nasa.gov/handbook/handbook_htmls/chapter11/chapter11.html>
something relevant I guess ("11.3.3 Band 6 Conversion to Temperature")
Nikos
[...]