My old Midwestern apartment had radiator heat. The radiators would clank noisily in the night, but the clanking made me happy, like the ringing of a bell for a Pavlovian dog. I knew heat was on the way. Because I was at the whimsy of my landlord-controlled radiators, I would often find myself cold before the next burst of heat. I realize now that there was a way I could have prevented some cold hands and frigid times.
If you use radiators to heat your home or apartment, there is a simple thing you can do to conserve energy. You can put tinfoil behind the radiator. The tinfoil will reflect heat back into the room where people tend to live. This will reduce energy costs. You won't need as much heat to stay warm. It will also maintain the heat, keeping your apartment or home warmer, longer.
If you think it is tacky to have tinfoil on your walls, you can still cut out enough tinfoil to cover the space that is concealed by the radiator, but a frame of tinfoil around the radiator is going to reflect more heat back into the house. That bit is up to you.
How to Use Tinfoil to Increase Radiator Effectiveness/Efficiency
Tape the tinfoil to the wall with duct tape or two-sided tape. Make sure that the dull side of the foil faces the wall. The reflective side should face out. You should feel a significant increase in heat.
Radiator foil is also available at hardware stores.