Another important characteristic is whether a lamp can be used in a totally enclosed fixture. LED lamps use conduction and/or convection to move heat away from the LEDs. Improper thermal management, or use in an inappropriate environment, can affect an LED product’s performance and/or cause it to fail prematurely. There are no such concerns with halogen lamps. Half of the Series 20 LED lamps provided an explicit warning against using the lamp in an enclosed fixture. In contrast, only four products (1262, 1265, 1290, and 1296) indicated they are suitable for use in enclosed fixtures. The remaining products did not provide any information on the subject.