GigaBlox Rugged critical temperature

Initial tests with the Gigablox rugged gigabit switch showed the IC VSC7511 heating up by 75k to 95°C at an ambient temperature of 20°C. We would like to use the Gigabit Switch up to 80°C, but would then have an IC VSC7511 surface temperature of 155°C with the included heat sink. How can it be that they specify a temperature range of up to 100°C?

Through qualification testing, we can operate the board at 100C for over 1 hour while verifying network speeds exceeding 945Mbps on all ports.