Statistically, the number of EVs that catch fire as a proportion of their total population on the road is miniscule and way less than the number of conventional petrol, diesel or CNG vehicles that catch fire. Also, the extent of damage that a conventional vehicle can cause when it catches fire is far more than in an EV. In a petrol vehicle, there is a combustion or a blast taking place all the time in the engine so the temperatures and risk is far greater. So the vehicle uses active cooling methods like a radiator with a fan and a coolant to keep the temperature under check. In an EV, the temperature doesnt really go very high so similar sophisticated means of cooling is not required but there is still always a risk so good ventilation and thermal management system would still be needed to make them more secure.