Temp guage

[KPS]

Hi Guys,

Was driving yesterday and whilst sitting in traffic i noticed the temp gauge just going above 90. Only went up by a very little bit and soon as I started driving it went back to normal. Any thoughts on what this could be - im assuming thermostat. But i know that means a belts off job. Cambelt was changed at 80 something thousand miles and now is currently on 110,000. It was done by a main dealer so dont know if they changed thermostat and tensioners, etc, etc. Is it safe to drive until i next get the belt changed or do I need to get it sorted asap. Also vague price for cam belt change including thermo and water pump etc etc?

Thanks guys