'70 MGB GT - Heater question

[Gary Davis <GDAVIS@ibr6gw80.gp.usbr.gov>]

Good Friday morning . . . .

Even though I realize the engine transfers considerable heat to the
cockpit (especially in the GT), I suspect my heater may be "on" all the
time.  The fan's not running, but I'm curious about the heater element. 
How would I check this out?

Thanks for the advice in advance - Gary Davis
(still on jackstands awaiting correct-size tie rod ball joints)