Your ambient temperature will affect this. I've found that mine gets warm and seems to reach equilibrium in 30 minutes or so but I've been starting at 60-70F. You can bet the R7's case will get a good bit hotter when it's stuck in the sun and started up already at 140F+. The cooler the ambient temp the easier it is for it to relieve heat.
Well it's hot to the touch. Temperatures in south Texas have not been as hot lately maybe max was a little over 92 degrees F. I was just wondering if it would affect it's performance and longevity. Will find out in a month or two when temperatures are over 100 to 115 degrees.
According to the manual operating temp is 32 to158 degrees F. However it also says -10 to 70 degrees C. 70 degrees C is 158 degrees F but -10 C is not 32 F, it is 14 degrees F. If it bakes in the sun with the car off and windows up, it could exceed 158 F. My detector is mounted just under the RVM and it gets its own dedicated A/C vent pointed at it in the summer (when I can get away with it ).
From browsing around RDF it sounds like the R7 doesn't like heat too much on a hot summer day. I know it gets quite warm just using it indoors in an air conditioned environment. I poked around on the Jungle and found this as an idea to experiment with cooling. First concern is added weight...