Trich is just one of the many risks associated with undercooked bear, doesn't need to be brought all the way up to 160, 150 will kill it within a minute or two and 140 for 5 minutes or so is good to go, I believe even 130 is fine if you hold that temp for long enough...don't quote me on the timing though. Bear meat is delicious but don't play with fire, I never bother to get them tested just assume they all have it no matter what the percentage in my area is...ideally get the guts out and hide off right away and get it into the freezer as soon as you get home, at your first opportunity thaw it out and trim off as much fat as possible as it will go rancid fast even in the freezer. I shot a bear last month that I wasn't able to process before dark, he sat all night with guts in, hide on and it was a hot one the next day packing him out. I was a bit worried about that one but the meat is still great, main concern would be trimming off fat before it goes rancid, if you render it down once trimmed however it will be stable for a looooong time in the fridge.