1. A baby carrier
When you have a second child, you do not grow a second pair of arms (not so clever now, are you "mother nature" you cow). Without these extra limbs you have 2 options: try to look after 2 children with one hand each or try to look after one child with 2 hands and the other one with no hands. Weirdly, the no hands option is best. You can't do up zips, rescue Rah the lion from a puddle or wipe snot from a wriggly toddler with only one hand. No. you need to have both hands free to look after the toddler so you've gotta go hands free with the infant. Get a sling. Put the infant in it. Forget about the infant until it needs milk. Sorry neglected second born, no hands for you.
2. A television with BBC iPlayer
A television is vital for keeping small toddler hands out of trouble while you are trapped under a feeding infant. You can TRY to not use telly as a baby sitter during this time, but you will fail. Iplayer is an added bonus because you can choose the current favourite show even if its not the right time. Currently in our house this means Mr Tumble gets his wish that we "pleeease co-ome back aaaagain" several times a day. It's not ideal but neither is a toddler skull fracture from attempting to climb the bookcase or jump off the windowsill while Mummy is busy.
3. Stairgates, stairgates, stairgates
You need to be able to contain the one that can walk in any room of your choice while you attend to the baby. This is vital keep them safe from their constant urges to run into the road or fly down the stairs or climb into the oven or drink laundry detergent or empty the toilet bowl with their hands or eat your nail varnish. Toddlers hate it when you put them in handcuffs and shackle their feet to radiator pipes so stairgates are your only option here.
4. Friends with 2 small children
No one will quite understand the total mania that your life has become like other parents who are also doing it. People who have 2 bigger children are of no use here because they have blanked out the first year of their second child's life for the sake of their own sanity. The new-to-2 parents are also handy for the hallowed "play date". You NEED play dates, in which you put all children in someone's living room, take it in turns to get tea and cakes from the kitchen and occasionally cry on each other from exhaustion.
5. Twitter on your phone
For when your 2 child parents aren't around. You can use twitter for a quick 5 minute "zone out" while Mr Tumble is on. It works to remind you that there is a big wide world out there (BBC news twitter feed). Or to make you laugh. On a bad day you can tweet your parenting despair and get 25 people respond with sympathy or (even better) with a tweet about how their day is even more disastrous! On a good day you can share your triumphs like "I have washed my hair" or "no one cried for 3 whole hours today".
What's in your survival kit?