All polycarbonate materials, where they're used externally as a pergola, shade or an extension off the side of a house unenclosed, when there's a local flame source acting on it, it can melt and drip away like honey from that flame source without burning itself.

If polycarbonate is used as a skylight in the house itself, or as a window glazing element, it's going to potentially melt or fall away from a relatively small heat source and therefore open up the house and not act as a barrier for embers to get into things.

The only times we've really seen it burn and act as a flame source is when it's formed quite a significant wet molten puddle on the ground and then continued to be heated by an adjacent source until you finally get that puddle to burn.

In contrast Fiberglass (that typically used a polyester resign) skylights and translucent panels are extremely ignitable and will, in themselves, carry a fire from a gutter line all the way to a house.

If these fibreglass elements are present, or used in your house, they should be removed and replaced by glass or polycarbonate alternative.

Skylights come in every shape and size but, unfortunately, they create an inconsistency in the roof profile...a place for debris to build up on and prop against...another potential place where debris can accumulate and localized flames can start to play on the adjacent sky lighting elements. So we really have to put that on the table as a sensitive or vulnerable element.

Evaporative coolers are quite problematic in fires. They burn prolifically unless specifically designed with fine meshes and non-combustible filters, and the whole box is essentially non-combustible.