Temperature plays an important role in the curing process of the resins used in composites. Many of the resins are setup for room-temperature curing. This requires that the ambient room temperature is ideally set between 65 and 75 degrees. And that the resin itself is near this temperature.
The old rule of thumb is that a drum of resin takes about 24 hours to get to room temp when moved in from shipping or storage.
These room temperature cured resins have windows of open working time before the curing cycle begins to happen. Elevated temperatures in the summer can cause havoc, but can be managed with special mixtures and ingredients.
Some resins cure with time and elevated temperatures, which are achieved with the use of ovens. These allow for nearly unlimited open working time before cure. When things are satisfactorily placed, the temperatures are elevated to start the cure process.
UV Light is another curing mechanism that has special applications and takes the temperature consideration away. This has a big use with the infrastructure restoration industries working onsite and underground. It is much more of a specialized niche application.