a heated fuser roller and backup roller fix toner on a sheet passing therebetween . these rollers are separated during nontoner fixing periods and normally closed for a predetermined early closure period prior to arrival of a sheet at the nip between the rollers . the immediate past history of fusing activity is monitored to determine whether the early roll closure is to be inhibited , a situation existing whenever the immediate past history indicates that steps must be taken to prevent backup roller overheating . the past history monitoring is performed by direct backup roller temperature sensing , timeout circuit operation or the like .