No one will get on you for acting responsibly and in best interest of the animals that you keep, regardless of your age. However what are you going to do in 3 months or so when you still have no job your $400 bucks gone and you still need to feed your snake. What are you going to do when you are 18 and you now have a 15'er and you are going to go to college, or join the military or whatever you choose to do to become a productive member of society. Impulse purchases hurt the snakes and the hobby. As far as the heating pad goes I would say if you have the heat pad hooked up to a thermostat then leave it on all the time and set the thermostat to the temps that you are wanting. If you do not have a thermostat then shame on you. you are jeopardizing the life of your snake. They can not sweat so if the heat pad goes haywire (which happens quite often) you will fry your snake since it has no where to cooler to get away. You also need to ensure that the room that the snake is in has border line extreme ventilation. Have a fan circulating air through the room, since you are still using a fish tank. The circulating air will help a little. Also, get rid of the carpet, and figure out a plan on how you are going to care for your snake over the next few months without any money because it can get very costly very quickly. You need to find a way to monitor and maintain proper humidity levels also. Your burm should be at 70-80% humidity so go get a guage. Being in a fish tank you are going to have to mist quite often because most of your humidity will escape out of the top of the cage. i do not know what else to say, I just think it was a poor choice you made to purchase this snake at your present time in your life. Todd