Typically gel batteries don't gas, but in the event they do, the same explosive mixture is produced. Gel batteries are no more sensitive to temperature than liquid batteries, and might even be less sensitive regarding gas emissions. However, effects from gassing a liquid battery can be hidden by the addition of water to the cells. That can't be done with a gel battery. There is no safety difference related to temperature between gel and liquid batteries, just an economic difference.
Battery type makes no difference.
In the case of the explosion mentioned earlier a plethura of things probably went wrong. While there was an Ample Power Energy Monitor onboard, battery temperature sensors had not been connected, and no alarms had been activated in the Energy Monitor. The first temperature sensing alternator regulator was the original 3-Step unit introduced by Ample Power Company in 1987. Alarms have been available since 1989.