Hi, All:
I tried setting up a temperature sensor (Dallas 18B20), and it got really hot, even though I was sure I had the pins connected properly. I reversed the sensor, and am now getting temperatures of -37 – which it is not, thankfully 
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Can anyone see what I’m doing wrong? Is my sensor defective? It goes without saying that I am a novice in all of this, so my apologies in advance for asking such a simple question.
Michael
The picture you posted, was that before or after reversing it?
Also, don't ever reverse stuff "just to see if that works". It's not going to work, and there's a big chance you're going to destroy something in the process. Rather, check datasheets, do some googling, or ask if unsure. Depending on what you're reversing, that can actually be dangerous. Batteries and capacitors for example do not like being reversed all to well, and might explode and/or catch fire.
I’ll keep that in mind in the future. I did what I did because in the video the author said if you hooked it up incorrectly it would get hot… After it happened, I did look around, and AFAICT everything is hooked up correctly (but the image is after reversing the sensor, it’s cool to the touch).
What video would that be?
In electronics when things get hot, when they're not designed to do that, there's a very good chance you've broken it somehow. The wiring above seems to be okay, so if you've got a spare one, you could try that.
Additionally, you might want to start using more 'appropriate' colors for wiring to make things easier. Red is generally used for + and black for -. Sticking to that format makes it easier to follow, and keeps things consistent 
The video is “Introduction to IoT Programming with JavaScript”, by Patrick Catanzariti, published by O’REILLY last year.
Unfortunately I’ve burned out (possibly) my one-and-only thermometer sensor, I’ll try and snag another somehow.
Thanks for the advice about the wiring scheme colors – I was aware of it but being lazy, I’ll try and adhere to it in the future.
And just to follow up on my own post … at one time the Spark (or Photon) Maker Kit used to ship with a TMP 36 temperature sensor, and that was what was described in the video that I was following. So when it said grab the temperature sensor – something that looked like a transistor – I grabbed what my kit shipped with – a DS18B20 – and Googled it to discover that, yup, it’s a temperature sensor. Unfortunately, the two have the ground and 3V3 pins switched 
