Strange things...

You are preparing for long course racing (half IM or IM).  You are working hard, doing more hours, and doing more volume.  Many folks are training harder then they have ever in their lives.  This can make your body react in strange ways.

One is heat.  Specifically, your body heat.  You may find that your legs are quite hot quite often.  Or that you sweat for long periods of time after training.  After hard work, your body will begin to repair itself.  The repair process is an exothermic chemical reaction.  In other words, it generates heat.  So, muscle tissue getting hot to repair should not be surprising.  The key things to do about this are:

1. Nothing.  It is normal.
2. Drink more.  The reactions require a lot of water so you will need to replace it.  Also, it helps lower body temperature.
3. Ice.  Ice baths are great to help the healing process and lower heat.  Too much heat can damage the recovery process.  Ice packs work also if the ice bath is too much for you.

You may also experience night sweats.  This is the body working hard to recover.  Again, cooling and drinking are important.  And a towel close to the bed may help :-).

So, don't be surprised if strange things happen.  As your fitness increases, these episodes will decrease.  However ice is always your friend so use it often.