To answer your specific question, there are essentially two ways to provide push notifications to an email and/or text message with temperature/humidity alerts that we find useful for a variety of reasons. If you have internet available in your RV/home, a system that connects to your existing network such as the
Temp Stick works very well for around $60 with no ongoing subscription fees. David Bot (OutsideOurBubble) did a review of it
here..
The other way is if you do not have a dedicated/always on internet source. The system that we use and that has worked very well is the
RV Pet Safety Monitor. They have two systems-one that works on ATT and the other on Verizon. The Verizon system is what we use and is a bit pricier but in my opinion is a more reliable system for our travels. One downside, there is an ongoing subscription charge but, factor that as you consider options. Their phone app is excellent allowing you full control over the system. I can highly recommend this product. By the way, they currently have a coupon code available (4glite) that you enter on checkout and it drops the price to $99.
So, look at your costs for your specific situation (dedicated MIFI, etc) vs. dedicated temperature monitor with ongoing subscription fees and determine what is best for you if you plan to provide temperature monitoring to your RV, car or home.