Learn about sleep modes and if its only to log temperatures run the micro with the internal 8Mhz RC and with clockdiv on, the slower it is the less power it uses, dont put any unecessary always on leds and minimize resistor use.
Learn about sleep modes and if its only to log temperatures run the micro with the internal 8Mhz RC and with clockdiv on, the slower it is the less power it uses, dont put any unecessary always on leds and minimize resistor use.