Anyway to monitor temps inside TT when gone for day? ideas?

Years ago I picked up a wired indoor/outdoor thermometer which allows me to manually reset the Min/Max tracking.

The "outdoor" wire broke off years ago, but I still keep the module inside my car to monitor those temps (for similar reasons). I always wanted to be able to prove what the car's temperature was when leaving dogs in there inside crates. I'm now at the time of year when I cannot leave them, even for a "minute or two"