On the B727 ,didn't have any Indication of 'how warm the brakes were'but if the station stop was less that 45mins-with high ambient temps one was advised to allow the gear to dangle in the slipstream for a period to avoid 'Hot Gear/fire 'indications...
Used to watch BA747 dangling the gear enroute to SEA from YVR,to have the gear 'cool' for the heavy Takeoff ex SEA-LHR.
On the 320 we had temp' indication-Auto brake LOW provided uniform temps which didn't seem to be a problem at Takeoff time,as opposed to heavy footed arrivals requiring some delays (or the gear fans if equiped)....
cheers..
