First, a general comment: celsius affects only those mechanisms whose source code specifications explicitly use celsius. For mechanisms specified with NMODL, this means that the ASSIGNED block must declare
and that some equation block (e.g. FUNCTION, PROCEDURE, DERIVATIVE, BREAKPOINT) contain an assignment statement whose right hand side involves celsius.
Next a comment about temperature
effects on spikes: warming makes spikes smaller for two reasons. It speeds up gNa activation and inactivation, so depolarization produces briefer inward current and less net depolarization (dV = dq / C, where dq = total charge entry). It also speeds up gK activation, which diminishes the net depolarization that the Na current can produce (plot iNa and iK vs. t and you'll see that, even at 6.3 deg C, iK is only slightly delayed compared to iNa--indeed, unless you look very closely, their time courses seem to overlap almost completely).
The experiments from which the parameters of the Hodgkin-Huxley squid axon model were derived were performed on cold-adapted invertebrates in very cold sea water. That model is not going to generate fast spikes, and it will not produce robust spikes at warm temperatures. If you need fast spikes, or spikes that hold up at warm temperatures, you'll have to use mechanisms based on experiments on vertebrate neurons, preferably mammalian, at warm temperatures.
A caveat: there are very few studies of the effects of temperature
on voltage-gated channels, and there is good reason to believe that their Q10s are not 3 (see
How to implement temperature