Not quite. You RHP isn't there to provide a hot spot. It's there to make sure that your ambient temperatures stay at what you set them. I have the thermostat set at 80F so if my cage is cooler then the RHP kicks on. Once it reaches the set temperature, it turns off (the Herpstat controls the temps).
If the RHP was at 90F degrees at all time then your whole enclosure will heat up to 90F.
Some people think that you need belly heat of 90 for digestion, but that's not true. As long as you provide 80-84 ambient temps, you'll do just fine.