Being drummers, we often have the biggest burden next to the sound system as far as set up. In hot summer months I often have no choice but to have drums packed in a hot vehicle and head straight to the gig after work. Letting drums sit in a car all day where temperatures reach well over 100 degrees is not an ideal situation but through the years I have not had any problems with warped or cracked shells. The key is patience and applies to summer or winter gigs. Try to arrive to the setup a little early and unload your drums. Open up the lids and let the drums sit in their cases or bags for about 10-15 minutes. This will allow the shells to get acclimated to their new climate. Most of the time drums will have to be retuned due to heads stretching in extreme temperatures. Another key to a good performance is to take care of you and stay hydrated. We are not always aware of how much we are sweating so drink plenty of water! Keep a towel handy to get rid of excessive sweat. I can't tell you how many times I've had sweat drip in my eyes and had to finish a song with my eyes closed because of the burning salt. Sunglasses are highly recommended when playing outside. Many times a stage setup will be pointed directly into the setting sun and this is very hard on unprotected eyes. Lastly, playing outside usually means you are playing loader. Always wear hearing protection to guard against excessive monitor mixes and those deadly rim shots and cymbal crashes. Enjoy your summer gigs!