How do we reconcile the clock hypothesis in special relativity with the Unruh effect? The first says accelerating clocks tick at the same rate as their instantaneous velocity and the later says an accelerating observer records a temperature rise not observed by an inertial observer. To keep it simple, consider an accelerating and inertial observer passing right by each other. Seems like temperature changes caused by acceleration [the Unruh effect] would cause energy changes and hence [gravitational] clock changes. Do we just ignore this in SPECIAL relativity? Do we say it's just an 'instantaneous' differnce so it can't be observed? Is the observer instrument not 'warmed' by the background she observes? [That's impossible,,,nothing would register!] or something else? thanks!