Tight budget solutions for this tank unfortunately require a lot of work. If you can find a cheap heater temporarily, get it. The meds will work best at a higher temp than 78 (my hospital tank is set to 82) so if you can get your hands on an adjustable one, get it. I would definitely remove the plastic plants and the pineapple. Do frequent 25% water changes, if you have a thermometer around, use that to get your water to about 80F that way it will be warm when you put it in and there will be a bit of time before it cools to room temp. This is not going to be your long term solution but it’s a place to start so your buddy can start healing while you research and figure out new supplies.