You shouldn't need to do inittherm repeatedly - just once. It starts the chip doing continuous conversions - or should do, if the config byte is set up for this (which it should be). Writing the config byte is dangerous, as I said before.

It takes between 0.5s-1s to do a conversion. Read temperature reads the result of the last conversion.

If you're trying to prevent HDD damage at low temperatures, use GPIO16; you can use this to hold the HDDs in reset, which puts them into deep sleep mode. The initial boot code has stuff in there to do this, which is currently disabled; the delay on reading the thermometer would add ~1s to boot time as you wouldn't be able to let the drives out of reset until you'd read the temperature.

Hugo