I am going back about 15 years so I dont have photos of the set up, but it did work well the couple of times I did set it up.
The heater all fitted in an old suit case, these days one of those 40L plastic buckets would do the job.
I built a small wooden box to enclose a Falcon car heater core fitted with garden hose to a small electric water pump, along with the Falcon (for fan,no GMH stuff in my camp!) blower fan. I used all of the old Falcon's control system for the fan speed - a rotary switch and a few resistors. These days I would use an electronic speed controller on both the pump and the blower motors. On low speed an old car battery ran the fan all night and produced almost no noise. To feed the heater core with hot water I simply had a length of copper tube about 6ft long bent around to cover about 2 sq ft with long ends coming out next to each other and terminated with garden hose fittings. The rest is pretty much as you imagine.
As I used a self priming pump , it was simply drop one end of one hose into a bucket of water and start the pump until water came out of the other hose from the heater core. If you wanted hot water for washing up and cleaning hands, you left it all like that. Over time you ended up with a bucket of warm water and warm air in the tent ( in those days it was a centre pole Traveller) .
The copper coil of course goes into coals of your fire pit or the park BBQ.
If you do this a couple of things you have to do- have a fire you can leave unattended for a few hours , DONT LET THE PUMP STOP RUNNING or run dry, have decent length hoses ( I had 20ft lengths because I got them for nix) and dont use plastic Gardena hose fittings (they dont seal well once the hoses warm up), brass barb and jubilee clip connections worked well.
If you were staying for more than one night, a trench from the fire to the tent of about 2" deep, bury hoses and the heating efficiency went up a lot.
A bit of work, but no fumes to worry about, and kept the lady of the day happy .
Long term - she didn't like long drops , water not out of a tap, not being able to talk to some one for 6 hours about nothing, or waking up at daybreak to watch the sunrise. She used to think she was punishing me by not talking to me- I thought it was heaven! Glad she is my ex now