The alarm on my carbon monoxide detector just went off, what do I do? 

Check the unit and batteries for proper functioning.  If they appear to be working properly, contact the fire department immediately.  Carbon monoxide is a tasteless, odorless gas.  Over exposure can result in death.  It is a good idea to have the Health Department check the carbon monoxide levels in your home, even when there is no obvious problem.  A good time for this test is the beginning of each heating season.