Ok I just checked it out a bit. There's no reason to do 3e300. 1e300 also works, why pick a random number like 3 for the multiplyer. Anything * e300 gives infinity in this game. In fact it can be even less than that.
The smallest whole number multiple * exponent needed to get infinity is 4e38. The smallness decimal (to the thousandths place) number multiple * exponent needed to get infinity is 3.403e38. Just for ease of remembering though, I just use 1e100.

Also I found using -infinity you get something that freezes anything it touches by forcing it to -infinity uppon contact. This basically an absolute 0 object that forces anything else it touches to absolute 0, and does so irreversably. I then wondered wonder what happens though if something infinitely hot touches something infinitely cold cause I learned in math class that inf minus inf is undefined. Well what I found happened is the entire thing then gets set to a temperature of NaN (Not a Number). However this behaves as a -infinity. I'd been expecting it would have crashed the game or produced some other weird effect or glitch but it seems that NaN is treated as -infinity for some reason.

This is really interesting...by changing some things you have more strange stuff...I like it! :D
If you do this with other materials more interesting stuff happens!

Try dumping +inf temperature lava into a metal bucket set to -inf. The lava and metal will both metal and lava will then get set to NaN temperature when they touch. The lava itself will get strange colors. Like normal lava it is liquid, however it will freeze water (like any other NaN temperature substance), burn flammable stuff like normal lava, get strange colors in it (unique to NaN temp lava), and (like any other NaN temperature substance) will set any other substance it touches to a temperature of NaN.

In addition, NaN temperature substances (while they behave cold to water, and freezes it, and appears super cold in the "heat view") they actually will not detonate the C-5 cold explosive, but -inf temperature substances will detonate the C-5 cold explosive. Thus showing that NaN is a kind of glitchy temperature condition.

you could try setting the life of spng to +inf values. You get strange colours that way. Also, try setting the life of hswc to -1.

Try putting water on inf , it explodes into some kind of steam that stays put, normally, and if you spread it with air, chaos starts, it melts anything, and is more devastating than the worst bomb.

Or even better, put a small square of BMTL, GLAS, WAX, etc, ambient heat on, make it's temp 1e100, and hell unleashes. It melts really anything meltable (coal will turn to sparkcoal), and makes pressure break (nan)