text: No, you can't be allergic to heat from a radiator, but you could be allergic to something used on the radiator (such as paint or a cleaning solvent) that is activated when it heats up and releases into the area.\n\nIf not that, radiators have a different effect on the moisture levels in a room than most other forms of heat. You might want to check the humidity levels in your place as high or low levels of moisture in the air can exasperate cold-like symptoms.