diff --git a/src/data/download_participants.R b/src/data/download_participants.R
index a067d08b..c5115e8f 100644
--- a/src/data/download_participants.R
+++ b/src/data/download_participants.R
@@ -18,6 +18,7 @@ for(id in 1:nrow(participants)){
     device_id <- participants$device_id[[id]]
     brand <- ifelse(participants$brand[[id]] == "iPhone", "ios", "android")
     label <- ifelse(participants$label[[id]] == "", "EMPTY_LABEL", participants$label[[id]])
+    label <- iconv(label, from = "UTF-8", to = "UTF-8", sub='')
     start_date <- format(as.POSIXct(participants$timestamp[[id]] / 1000, origin = "1970-01-01", tz = timezone), "%Y/%m/%d")
     if(!(device_id %in% ignored_device_ids)){
         pid <- paste0("p", ifelse(id < 10, paste0("0", id), id))
diff --git a/src/visualization/battery_consumption_rates_barchart.py b/src/visualization/battery_consumption_rates_barchart.py
index e91e6e85..55c5f064 100644
--- a/src/visualization/battery_consumption_rates_barchart.py
+++ b/src/visualization/battery_consumption_rates_barchart.py
@@ -18,7 +18,7 @@ def getBatteryConsumptionRatesBarChart(battery_data, pid):
 battery_data = pd.read_csv(snakemake.input["sensor"], parse_dates=["local_date"])
 pid = snakemake.params["pid"]
 
-with open(snakemake.input["pid_file"]) as external_file:
+with open(snakemake.input["pid_file"], encoding="ISO-8859-1") as external_file:
     external_file_content = external_file.readlines()
 device_id = external_file_content[0].split(",")[-1]
 label = external_file_content[2]
diff --git a/src/visualization/compliance_heatmap.py b/src/visualization/compliance_heatmap.py
index 3d448c86..d2e37c66 100644
--- a/src/visualization/compliance_heatmap.py
+++ b/src/visualization/compliance_heatmap.py
@@ -27,7 +27,7 @@ def getComplianceHeatmap(dates, compliance_matrix, pid, output_path, bin_size):
 pid = snakemake.params["pid"]
 bin_size = snakemake.params["bin_size"]
 
-with open(snakemake.input["pid_file"]) as external_file:
+with open(snakemake.input["pid_file"], encoding="ISO-8859-1") as external_file:
     external_file_content = external_file.readlines()
 device_id = external_file_content[0].split(",")[-1]
 label = external_file_content[2]
@@ -35,7 +35,7 @@ label = external_file_content[2]
 phone_sensed_bins = pd.read_csv(snakemake.input["sensor"], parse_dates=["local_date"], index_col="local_date")
 
 if phone_sensed_bins.empty:
-    empty_html = open(snakemake.output[0], "w")
+    empty_html = open(snakemake.output[0], "w", encoding="ISO-8859-1")
     empty_html.write("There is no sensor data for " + pid + "<br>Label: " + label + ", device_id: " + device_id)
     empty_html.close()
 else:
diff --git a/src/visualization/heatmap_rows.py b/src/visualization/heatmap_rows.py
index e75117cb..81148511 100644
--- a/src/visualization/heatmap_rows.py
+++ b/src/visualization/heatmap_rows.py
@@ -30,7 +30,7 @@ sensor_name = snakemake.params["table"]
 pid = snakemake.params["pid"]
 bin_size = snakemake.params["bin_size"]
 
-with open(snakemake.input["pid_file"]) as external_file:
+with open(snakemake.input["pid_file"], encoding="ISO-8859-1") as external_file:
     external_file_content = external_file.readlines()
 device_id = external_file_content[0].split(",")[-1]
 label = external_file_content[2]
diff --git a/src/visualization/overall_compliance_heatmap.py b/src/visualization/overall_compliance_heatmap.py
index 1a6a42ad..66450baf 100644
--- a/src/visualization/overall_compliance_heatmap.py
+++ b/src/visualization/overall_compliance_heatmap.py
@@ -47,7 +47,7 @@ for date_offset in range(6,-1,-1):
 sensors_with_data_records, valid_sensed_hours_records = [], []
 for sensors_with_data_individual, valid_sensed_hours_individual, pid_file in zip(phone_sensed_bins, phone_valid_sensed_days, pid_files):
     
-    with open(pid_file) as external_file:
+    with open(pid_file, encoding="ISO-8859-1") as external_file:
         external_file_content = external_file.readlines()
     device_id = external_file_content[0].split(",")[-1].strip()
     label = external_file_content[2].strip()