B737 FLT CREW EXPERIENCES COCKPIT WINDOW OVERHEAT AFTER TKOF AND A SECOND WARNING IN CRUISE CAUSING WINDOW CRACKING AND DELIMITATION. FLT CREW DIVERTS TO NEAREST SUITABLE ARPT FOR UNEVENTFUL LANDING.

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AFTER TKOF AT 800 FT AGL MASTER CAUTION (ANTI-ICE) ILLUMINATED ALONG WITH R; SIDE WINDOW OVERHEAT LIGHT. COMPLIED WITH ENTIRE PROC IN QRH. AFTER 5 MIN COOL DOWN PERIOD; WINDOW REMAINED IN OVERHEAT CONDITION. UPON INSPECTION OF ALL WINDOWS WE NOTICED THAT THE CAPT'S FRONT WINDOW (L1) HAD A SMALL AREA OF POSSIBLE INNER PANE DELAMINATION AND DISCOLORATION AT TOP CTR OF GLASS. THE CONDITION OF THE (L1) WINDOW DID NOT WARRANT FURTHER ACTION OTHER THAN MONITORING. AFTER APPROX 20 MINS OF CRUISE FLT THE MASTER CAUTION (ANTI-ICE) ILLUMINATED ALONG WITH THE L FORWARD WINDOW OVERHEAT. INSPECTION OF CAPT'S (L1) WINDOW REVEALED HORIZ CRACKING WITH DELAMINATION ACROSS THE ENTIRE WIDTH OF WINDOW. WE IMMEDIATELY COMPLIED WITH THE PROC FOR 'USE OF COCKPIT OXYGEN MASKS' AND COMPLIED WITH QRH PROC FOR 'WINDOW OVERHEAT.' WHILE SLOWING THE ACFT WE HEARD AND SAW MULTIPLE CRACKS RAPIDLY DEVELOP. WE DECLARED AN EMER; REQUESTED IMMEDIATE DSCNT; NOTIFIED ATC; DISPATCH AND THE CABIN CREW OF OUR DIVERSION TO ZZZ. WE WERE VECTORED FOR A VISUAL APCH. CAPT LOWERED SEAT AND FO ACCOMPLISHED SAFE AND UNEVENTFUL LNDG.