What year is it, what are the specs? When you say 151 degrees F, is it the CPU, or another internal/external temperature measurement?
Knowing these things will help people who know about this stuff determine whether it's normal (within design parameters) or not. If it is, whether you're comfortable with that is down to you 👍
Yeah it would also help if you posted what you're doing while you're seeing temps of 66. If it's staring at the desktop with no apps open and doing nothing (idle), it's a little on the warm side. Not dangerous or anything.
If it's while you're browsing the web, that's pretty much the standard temperature I found on my 2020 MBA i5. Definitely felt it on my lap and it was a bit uncomfortable, but not hot enough to melt the chip or anything.
My MBA from 2015 hits 100c for hours on end with no issues whatsoever. It's designed to reach the maximum safe temps and stay there by changing the speed. If you can deal with the fan noise, it's really not a problem.