Non standard departures on the southampton departure routing, where a/c have been taking off and been limited to climb initially to 4000ft, hope this helps, but often many resrtictions on VOR departures north and south of LHR, mainly for a/c heading to the states or south bound. I believe there is one departure routing where a/c climb straight ahead to 2 miles from heathrow or 2 DME, before making a right turn to head 220 degrees, then further ascend ing to 6000ft.
hope this helps
all the best, you just got to relax especially in this heat!