What did you use to raise the head of the cot mattress?

[Tinks]

We did phone books under the legs too.

[KimB]

I used the good old bricks under the cot and it worked a treat.

[ShootingStar]

We used several rolled up towels for DD.

[starangelk]

We also used a towel, this massive massive big beach towel folded/rolled up.