Dryer Temps With A Single Heater
I have to disagree on this one. The water in the fabric prevents the fabric itself from overheating, regardless of the input power. As the fabric loses moisture, it begins to steadily heat up, and the remaining water which evaporates out of it becomes gradually hotter. This is reflected on the exhaust temperature to the extent delicate drops the heater at a lower exhaust temperature, while normal drops the heater at a higher temperature. In simple terms the exhaust temperature is always equal to the fabric temperature.
I know this because I've used Whirlpool based dryers for 15 years now. Delicate really is delicate, medium really is medium, and high really does the clothes very, very hot. The fabric temperature before cool down, even when the time dry cycle has been reset, always reflects the temperature knob no matter the fabric inside. Same for the door, the door is warm during delicate heat, painfully hot on high heat.
In fact, whether or not the dryer is overloaded with towels or has only a few delicate items the heater does not shut off at all for the first 10 - 40 minutes of drying- with larger loads taking longer for the heater to turn off. Only when the fabric gets to very roughly 35% moisture does the heater finally turn off. It comes back on soon though. As the clothes get dryer the heater on time steadily decreases, while the heater off time increases. This is how/why auto dry works, in that the timer does not advance until the exhaust temps open the cycling stat, indicating the load is close to being finished. The more time the cycling stat spends open, the less moisture there is the fabric to keep exhaust temps down.
GE dryers are another story, and a perfect example of GE being to smart for their own good. GE advertising brags how GE dryers do not yo-yo their temps as much as competitors but it does nothing to increase performance or fabric care. I had a GE dryer, my opinion of it is about that of its companion washer. It had two heaters, and upon starting the cycle the drum inlet thermostat would remove the first heater abut 5 minutes into the drying. This left only one heater, which greatly increased drying time as less BTUs was being put into the drum.
I was referring to Henene's reply that a dryer must have two heaters not to scorch items. Whirlpool dryers have one heater, with a high inlet temp, but IMO have the best fabric care in the world. The more I look at dryers, the most I like Whirlpool, by far. 
