Comparison 1. Warmed vs room temperature intravenous fluids.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Temperature at 30 minutes after induction	9	374	Mean Difference (IV, Random, 95% CI)	0.41 [0.24, 0.57]
1.1 Elective caesarean section	4	207	Mean Difference (IV, Random, 95% CI)	0.44 [0.12, 0.76]
1.2 All other surgery	5	167	Mean Difference (IV, Random, 95% CI)	0.39 [0.26, 0.51]
2 Temperature at 60 minutes after induction	8	312	Mean Difference (IV, Random, 95% CI)	0.51 [0.33, 0.69]
2.1 Elective caesarean section	2	105	Mean Difference (IV, Random, 95% CI)	0.60 [0.01, 1.19]
2.2 All other surgery	6	207	Mean Difference (IV, Random, 95% CI)	0.47 [0.30, 0.64]
3 Temperature at 90 minutes after induction	3	109	Mean Difference (IV, Random, 95% CI)	0.54 [0.04, 1.04]
4 Temperature at 120 minutes after induction	4	149	Mean Difference (IV, Random, 95% CI)	0.74 [0.31, 1.17]
5 Temperature at end of procedure/arrival to PACU (simple design)	11	682	Mean Difference (IV, Random, 95% CI)	0.63 [0.28, 0.98]
5.1 Elective caesarean section	3	205	Mean Difference (IV, Random, 95% CI)	0.56 [0.08, 1.04]
5.2 All other surgery	8	477	Mean Difference (IV, Random, 95% CI)	0.66 [0.19, 1.12]
6 Event rate of shivering	9	428	Risk Ratio (M‐H, Random, 95% CI)	0.39 [0.23, 0.67]
6.1 Elective caesarean section	3	145	Risk Ratio (M‐H, Random, 95% CI)	0.61 [0.36, 1.02]
6.2 All other surgery	6	283	Risk Ratio (M‐H, Random, 95% CI)	0.29 [0.14, 0.62]
7 Estimated blood loss	4		Mean Difference (IV, Random, 95% CI)	Totals not selected