Linked from
The 17 pages that link to Exothermic reaction, each with the reason it gives.
Thermal runawayRelated: Exothermic reactions can supply the heat that drives a runaway cycle.
Fire triangleRelated: Combustion releases heat that can maintain ignition and warm nearby fuel.
ExplosiveRelated: Rapid heat release can accelerate an explosive reaction and expand its gases.
LyeRelated: Dissolving solid lye in water releases enough heat to cause burns or boiling.