Examples include a fluid ejection system. The fluid ejection system comprises a fluid supply reservoir, a fluid ejection die, a fluid delivery subsystem, and a control engine. The fluid ejection die comprises nozzles to eject fluid and at least one temperature sensor disposed on the die to sense a temperature of the fluid ejection die. The fluid delivery subsystem fluidly connects the fluid reservoir and the fluid ejection die, and the fluid delivery subsystem comprises at least one valve to regulate conveyance of fluid from the fluid supply reservoir to the fluid ejection die. The control engine controls the at least one valve to thereby regulate conveyance of fluid from the fluid supply reservoir to the fluid ejection die based at least in part on the temperature of the fluid ejection die.