Do you have any references that indicate a morning basal temperature of 99.0-99.2 is normal? The work of Dr. Broda Barnes, often quoted on this forum, suggests this is much higher than optimum:
I'm not saying the word of Dr. Barnes is the final word. If you can cite something that contradicts it then I would retract my comments about 99.0 degrees body temp upon waking being indicative of hyperthyroidism.