This study will demonstrate whether an electric warming mattress can reduce the number of patients who get cold and shiver after elective cesarean section.

Peri-operative hypothermia (body temperature below 36 ºC) is a cause of post-operative complications and patient discomfort. Immediately post-operatively such discomfort is due to increased pain and shivering. Patients say that their time in the recovery ward is very stressful and this is prolonged if they become cold (hypothermic)or shiver. Subsequently, patients can suffer with increased risk of infections and delayed discharge from hospital.

For patients (and their babies) having Cesarean sections it is important to start breast feeding as soon as possible, but being cold may delay this.

For some types of surgery measures are put in place to stop patients becoming cold and thereby reduce the number of problems. However this is not the case with patients undergoing Cesarean sections because the special blankets through which hot air is blown to keep them warm are inappropriate for mothers giving birth by Cesarean section as it would make it difficult for a mother to have good skin-to-skin contact with her new baby immediately after delivery - an important part in the bonding process.

A solution is to use a new warming mattress. This has been shown to be safe and effective with some types of surgery, but has not been tested in Cesarean sections.

In the investigators study,the investigators will warm a group of patients undergoing planned Cesarean section and compare them to an unwarmed group to see if there is any difference primarily in post-operative temperature. Secondarily, the investigators will also look for differences in total blood loss, incidence of blood transfusion, wound infection, shivering, the immediate health of the baby, time taken to become fit for discharge from recovery, length of hospital stay and time to breast-feeding.

This project will be a randomised controlled trial comparing a warming mattress with current standard of care (no warming).

Prospective participants will be invited by letter and provided with a information booklet explaining the study and their rights. Informed consent will be taken in writing.

Patients will be randomised using a protocol created by the Trusts Clinical Investigations Research Unit who will use an Internet based randomisation system.

The researcher will not be blinded as it is not logistically feasible. The statistician analysing the results will be blinded to which group receives warming.

Study data will be collected manually on a standardised data collection sheet.

All enrolled patients will have their temperatures measured at specified times and will be observed for shivering. Data collection required to measure the primary outcomes will be complete by time of discharge from the recovery room. Data collection for secondary outcomes will be prospective and retrospective and will occur from time of anaesthesia through to one month after the procedure.

All patients will receive routine post-operative care.

To ensure any late complications are not missed we will interview the patients by phone one month after the date of their procedure.

Inclusion Criteria:

• All patients undergoing elective (planned) caesarean section under spinal or combined spinal and epidural (CSE) anaesthesia will be eligible.

Exclusion Criteria:

• Exclusion criteria will be those who refuse, who are unable to fully understand the trial or are under 16 years of age when presenting for their Caesarean section.
• Those that are unable to understand for language issues are excluded with regret due to the difficulties of obtaining interpreters at the time of caesarean section, in recovery and once at home for the telephone interview. Waiting for additional interpretation may delay the clinical management of the patient and also the patient may not be able to convey questions or concerns about the study through mail, email or telephone prior to attending.
• Patients under 16 years of age will be excluded from the trial for reasons of consent. Although a patient less than 16 years of age may have Gillick competence and therefore have the capacity to consent to take part in this trial, as a minor their parents may have concerns leading them to refuse trial entry. Child birth in minors can be very stressful for the patient, family and clinical team and we are keen not to add to this for the purposes of a study.