Our heating system in the truck is messed up

There’s something going on with the heating system in our truck. Of course, it’s probably been torn up for months, but I haven’t known about it because it’s been summertime. We have not needed to turn the heating system on in the truck since last spring, and now that we actually need it, it’s not working. The weather has really been cooling off lately, and it is definitely starting to feel like fall is on its way. I love the fall weather, but I absolutely hate feeling cold. There is no way in the world that I would be able to go through the whole winter without having a heating system in my truck. It’s one of those things that you just can’t live without when you live in this part of the country. During the wintertime, the temperatures here get into the single digits on a regular basis. You have to start using your oil furnace or your gas furnace in October, usually. And most of the time, you can’t stop using the heating system until sometime in the middle of May. so it’s really not something to play around with. I really have to get the heating system fixed before the weather starts cooling down even more. The problem is that I’m just not really sure what to do with the truck. I don’t know whether I should take it to a garage to have it looked at or if I should try calling a heating and cooling technician instead. I’ve never had a problem with a heating system in a vehicle before.