I've noticed this as well...although for my system it can take upwards of a minute (very poor laptop, can't even run Horizons

). For me, staying alive comes down to taking a different route on exploration scans. 0 throttle on jump, target arrival star while honking at 0 throttle, open system map while star scans, take quick look for anything interesting, THEN scoop and either head off to scan interesting targets or jump to next target. I never, EVER open my map while my throttle is open, unless I'm pointed towards something over 200,000ls away (occasionally its worth the trip, like for suspected water worlds/ELWs/Ammonias, or I'm seriously bored and just want to read for a few minutes

). I did make the mistake of map while scooping once...in my Asp...and the map never opened while I watched in horror while the heat spiked to 300%. Er, well, it DID open...about half a second before the eject sequence kicked me out...and I started at 20% heat. Won't do that again!