I have had these tests, repeatedly, over the past 30 years.
Most times, if the room was cold or cool, the clinician had trouble with the testing and had to call in a supervisor, etc. They had decided the difficulties had to do with the room temp (ambient air temp) and their machinery.
Other times, the room is warm.
I have found a Board Certified Neurologist, also certified in doing all of this type of testing. At the local teaching hospital, technicians do the testing under the license of a certified physician. Now I have the Neurologist, himself, do the testing, as he has a better idea of what he is looking for.
It appears, by using a heat lamp, they did want your body warm upon testing in this case.
I am sure they were using that method on purpose with you.
I don't do well with heat or with cold. Either one gets me into serious troubles.
I hope you gather some helpful information from your testing.