Remeber the fish tank colour strips/stickers that changed to show the colour on the side? The were accurate to 1*c so something similar could be made or looked at
These exist and were what I was talking about above. the technology that AP Racing and the like use in raceing cars is incredible.
For 1 season they made Berylium calipers for F1 before they were banned, excellent properties from an engineering standpoint, but the dust/swarf was cancerous, machining could only be done in 1 factory in ex USSR and one in USA, and the billet of material for each caliper was something over £10,000.
If you were to give them a ring I'm sure they would send you a couple of temperature strips to play with.