It really doesn't matter where the outside thermocouple junction is as long as YOU know where it is. For instance I have an indoor/outdoor inside my greenhouse with the "outside" lead positioned under a typar cover at plant level(plants are planted in soil). This "outside" temperature value from the thermometer face is telling me the temperature that the plants are probably experiencing under the cover. The "indoor" reading is the inside greenhouse (above typar cover) temperature. I reset the thermometer regularly after viewing the high and low maximum range for the day. It is great to be able to read a temperature from a remote location without having to navigate to that location... the indoor/outdoor thermometer will work great for that purpose even if you need to switch logic to understand where the reading is coming from. As far as temperature outside the greenhouse... it is nice to know how cold or hot it is but I don't have any way of controling it. I guess it could be a guage for wishful hoping that maybe the plants can get by for a few more hours before supplemental heat is needed.

Being a gardener and getting away for a few days is mutually exclusive unfortunately. Your best bet is to buy a timer that you can attach to the faucet. You leave the faucet turned on, set the timer for how often and how long to go off and you're good. A soaker or small sprinkler works well. Depends if all your plants are clustered close together. If they are spread around so one hose/sprinkler won't do the job, then you'll need a Y connector coming off the timer to as many hoses/sprinklers you need to keep everything watered while you're away. This is the only system I have found that works well. We like to head up north to cooler temps in summer and getting the neighbor to water for me (in exchange for my feeding their dogs when they are gone) did not work out very well...........she's a blonde, what can I say? kidding peeps, just kidding.

The higher ones.

Most lower-end machine do run the heating element (if they have an exposed element inside the tub) during the washing and rinsing phases, but it's only to assist in maintaining whatever is the incoming water temperature and perhaps raise it just a tad, not to heat from cold or lukewarm to hot. Any dishwasher, "old" or "new," that has a specific "sani" rinse or high-temp washing or rinsing option CAN heat quite a bit. How much depends on how the machine is engineered. Some models have a heating period limited by time and expect the incoming water to be around 120°F or so in order to reach the target "sani" temp. If the incoming water is too low, the time-delay will run out and the cycle will continue even if the target temp isn't reached. Others have a true thermostatic delay that holds the timer from advancing until the target temperature is reached regardless of how long it takes. Some brands (Bosch, Miele, Fisher & Paykel, and others) have thermostatic delay for ALL cycles to insure that the target temperature is always reached. These machines can work with cold water, but are typically connected to hot to help prevent very long cycle times as would occur when heating from cold.