good evening one and all
just in my humble opinion - the only time heat is generated in Epoxy resin or Polyester resin is
a) When one has the mix ratio wrong i.e. too much hardener to the resin - this generally generates a certain amount of heat. This, if in a combined space such as a mixing tumbler where one has a large concentration of the mixture - this may, if its polyester resin, bubble & smoke ^ dissolve and melt the plastic container that it is held in. Also noxious fumes will emanate into the air.
b) Epoxy resin, depending on the type (as there are as we know several types of Epoxy for various applications) tends to do the same as above but can become slightly more toxic if it reaches this stage SO DO BE WARNED
If your mixture is correct though, and you have mixed it in small quantities and spread it over the area thinly - one should have no problem with heat generation.
The things to be cautious about are - the materials which are being bonded together - glass fibre and wood - one will generally have no problems bonding with the polyester/epoxy based resins. Time to worry is when you have certain plastic hulls and oily timbers such as teak/Iroko which we have to use special glues/treatments for bonding.
John
ps remember heat + smoke make man take action and run fast